At 19, after two years of college in Berkeley, Fleischman took a cross-country bicycle and train trip, ending up living in a 200-year-old house in New Hampshire. The years there, living a modified 18th century lifestyle--wood heating, no electricity or phone--kindled an interest in the past and led to his historical fiction dealing with the Puritans' Indian wars, colonial peddlers, Philadelphia's yellow fever epidemic, and other topics.

His musical interests are reflected in his collections of poems for two and four speakers. Multiple points of view and a bridging of plays and prose have been hallmarks of his work, beginning with Bull Run, an account of the battle through the eyes of 16 different characters, continuing through Seedfolks, the 50-voice aural collage Seek, and Zap, which combines seven plays into one.

Born in Monterey, California, in 1952, Fleischman grew up in Santa Monica, the son of well-known children's author Sid Fleischman. "Growing up hearing the wonderful works of my father ... read aloud as they rolled out of the typewriter, I was exposed to books," Fleischman recalled in School Library Journal, "but was not a reader and certainly had no plans to be a writer." Instead of holing up in libraries as a youth, Fleischman and his sisters spent time on their bicycles exploring the streets and alleyways of their beach town. These explorations soon became foraging expeditions, as the children gathered other people's castaways from trash cans. However, while growing up in a writer's household the young Fleischman absorbed the elements of story without knowing it. In 1977, when he was about to graduate from college and was casting around for a suitable occupation, writing presented itself to him as a real possibility because he had witnessed his father's success as an author.

Fleischman's first book, The Birthday Tree, showed that he had potential as an author, and from that first book he has branched out into a wide range of themes and styles. Early young adult-books include the Edgar Allan Poe-and Nathaniel Hawthorne-inspired Graven Images and The Half-a-Moon Inn, the former a Newbery honor book. Fleischman blends his love of research and his musical approach to language into these works. "I write only a page or so a day," he explained in his 1989 Newbery acceptance speech, as published in Horn Book. "After several books it dawned on me that this was because I was writing prose that scanned, something that makes for slow progress." His "scanned prose," or verse-like writing with rhythm, meter, and occasional internal rhyme, is as close as Fleischman feels he can get to composing music, one of the loves of his life. "All my prose is written in 4/4 time," Fleischman explained.

The author's poet-like concerns for the rhythm of language is apparent in books such as Joyful Noise: Poems for Two Voices, in which Fleischman presents fourteen poems that celebrate the insect world, and Big Talk: Poems for Four Voices. The poems in Joyful Noise are onomatopoeic, their texts echoing the sounds made by the insects themselves, and are intended to be read aloud. Mary M. Burns, reviewing the poetry collection for Horn Book, called Joyful Noise a "marvelous, lyrical evocation of the insect world" and concluded that "Each selection is a gem, polished to perfection. If Paul Fleischman never wrote another book, his reputation would remain secure with this one." The Newbery committee agreed with Burns and numerous other reviewers, awarding Fleischman the 1989 Newbery Medal for Joyful Noise. Interestingly, the author's father, Sid Fleischman, had received that same award just two years previously. In Big Talk, which Booklist reviewer Gillian Engberg dubbed "perfect for classroom theatre," a color-coded text helps four readers collaborate on reciting the three poetic narratives: "The Quiet Evenings Here," "Seventh-Grade Soap Opera," and "Ghost's Grace." "The likely cacophony will bring giggles as readers work on getting the hang of all this big talk," quipped Margaret Bush in her review of the book for School Library Journal.

In addition to his passion for music, Fleischman is also fascinated by the past. Much of this he credits to his father's own love for research and history; he also noted in School Library Journal the serendipity that led him on a cross-country bicycle trip and to live in a 200-year-old house in the New Hampshire woods. It was a time of revelation for Fleischman, long before he thought of becoming a writer. He learned of seasons, of the names for birds and plants, and felt—in the absence of electricity—as if he were living two centuries earlier. Recalling his long list of novels, short stories, poems, and nonfiction books in School Library Journal, Fleischman declared that "None of those book would have been written had I not lived in that house."

Fleischman's abiding interest in the past has led him to create an impressive group of historical novels and nonfiction, ranging throughout his earliest fiction and continuing through such novels as Saturnalia, The Borning Room, and Bull Run, as well as through the nonfiction works Townsend's Warbler and Dateline: Troy. Focusing on the white man's treatment of both servants and Native Americans, Saturnalia is set in Boston in 1681 and plays with the idea of a world turned upside down, as during the Roman festival Saturnalia. The book focuses on a young Narragansett Indian boy in search of his twin brother as well as his heritage, both of which he lost six years earlier when his village was attacked by whites. "The writing is lyrical with somber tones, bright and lively notes, and quiet, thoughtful stretches," commented Amy Kellman in School Library Journal, adding that Saturnalia is "a very special book for a special audience." Booklist reviewer Denise M. Wilms concluded that "this absorbing story exemplifies Fleischman's graceful, finely honed use of the English language," while Raymond E. Houser noted in Voice of Youth Advocates that the novel "will challenge the most mature reader with its vocabulary and symbolic approach."

Fleischman deals in first-person narrative in The Borning Room, a novel that relates the life story of Georgina Lott. Georgina tells her story to a portrait painter called in to do her picture before she dies, and all of the action takes place in the borning room in which she was brought into the world. Fleischman weaves larger history, such as the U.S. Civil War and the underground railroad, as well as domestic history, into his fictional tapestry. Writing in Booklist, Hazel Rochman observed that "Rebirth comes through connection and loving memory and through art. And it comes through stories, like this one." Zena Sutherland concluded in the Bulletin of the Center for Children's Books that The Borning Room is "smoothly knit" and a "moving family chronicle."

With Bull Run, Fleischman highlights that well-known civil war battle, as seen through the eyes of sixteen different men and women. Samantha Hunt, writing in the Voice of Youth Advocates, described the novel as a "remarkable series of vignettes," comparing Fleischman's characterization to that employed by twentieth-century writer Edgar Lee Masters in his Spoon River Anthology. "Literally, this work stands alone in juvenile and young adult fiction," Hunt remarked, noting that Bull Run does for juvenile prose what Fleischman's Joyful Noise accomplished for juvenile poetry. A Publishers Weekly reviewer observed that, "like a Shaker cabinetmaker, Fleischman creates stories of deceptively simple design ... that resonate with grace and beauty," and concluded that Bull Run "is a tour de force that should not be missed." Carolyn Phelan concluded in Booklist that by "abandoning the conventions of narrative fiction, Fleischman tells a vivid, many-sided story in this original and moving book."

Fleischman also serves up nonfiction in his Townsend's Warbler. This book tells the story of two nineteenth-century naturalists, John Townsend and Thomas Nuttall, who made their way across the country in search of new plants and animals, including the tiny bird featured in the book's title. Lois Ringquist noted in Five Owls that "Fleischman brings to life the adventure" that lies behind the tiny stuffed bird in the natural history display. In Dateline: Troy the author employs a current-newspaper format to bring to life the events surrounding the Trojan War, juxtaposing the war as related by Homer against modern-day headlines. Shirley Wilton, writing in School Library Journal, noted that "What comes across in Fleischman's fine retelling is the universality of the human qualities of greed, treachery, and violence." Betsy Hearne concluded in the Bulletin of the Center for Children's Books that Dateline: Troy is a "thought-provoking book, classically austere in design, with a partnership of text and illustration unusual" in young adult works.

In addition to exploring the past, Fleischman also engages readers with fiction dealing with modern-day themes and problems. In titles such as A Fate Totally Worse than Death, Seedfolks, Whirligig, Weslandia, and Breakout he demonstrates the range of styles and themes that have made him such a versatile writer. Parodying teen-horror novels, Fleischman serves up a "funny, mocking, and ... surefire hit" with A Fate Totally Worse than Death, according to Julie Cummins in School Library Journal. "Lavishly dosed with comic hyperbole, his plot is good for some chuckles—and many groans," noted a reviewer for Publishers Weekly. In Seedfolks the author once again employs his multi-faceted narrative voice, "arraying voices like threads on a loom," according to a contributor to Publishers Weekly, noting that the novel weaves "a seamless tale of the advent of a garden in urban Cleveland and how it unites a community." Susan Dove Lempke, reviewing the same title for Booklist, concluded that the "characters' vitality and the sharply delineated details of the neighborhood makes [Seedfolks] ... not merely an exercise in crafts-manship or morality, but an engaging, entertaining novel as well."

Whirligig examines the aftermath of a teen traffic accident. Coming home from a party intoxicated and despondent, Brent tries to commit suicide, but instead kills a stranger—a talented and lovely high-school senior. His atonement for the crime, as set by the dead girl's mother, is to erect four whirligigs with pictures resembling the victim at the four corners of America. Brent's subsequent journey takes him not only across the United States but into his own psyche as well. "The brilliant Fleischman has written a beautifully layered, marvelously constructed novel that spins and circles in numerous directions," commented Miriam Lang Budin in School Library Journal. Another book for older readers, Breakout focuses on seventeen-year-old Del Thigpen, whose impetuous decision to fake her death and escape from her current foster home is frustrated by a Los Angeles traffic jam. While stuck on the freeway, Del has time to reassess her situation, and Fleischman threads his novel with a parallel narrative that shows an older Del—now a performance artist calling herself Elena Franco—reflecting on the shift caused by these ruminations. A Publishers Weekly reviewer explained that the novel, which "explores the way art allows people to re-examine their lives," is structured to "allow ... the real and imagined events to blend, supplementing and augmenting each other." While noting that Breakout "makes demands on its readers," Booklist reviewer Ilene Cooper added that the "artful, insightful" novel is "very much worth the effort."