Avi was born in 1937 in Brooklyn, New York. He became interested in writing during his senior year of high school. On writing he has said "I think you become a writer when you stop writing for yourself or your teachers and start thinking about readers." Avi also admits that writing is hard work and that on average, it takes him a year to write a book. He started out writing plays and moved on to writing for young readers once he had children of his own—two sons. Avi has written mystery, adventure, fantasy, and ghost stories. Two of his best-known titles are The True Confessions of Charlotte Doyle and Nothing but the Truth, both Newbery Honor Award Winners.