The title refers to the rabbits' destination, Watership Down, a hill in the north of Hampshire, England, near the area where Adams grew up. The story began as tales that Richard Adams told his young daughters Juliet and Rosamund during long car journeys. As he explained in 2007, he "began telling the story of the rabbits ... improvised off the top of my head, as we were driving along." He based the struggles of the animals on the struggles he and his friends encountered during the Battle of Oosterbeek, Arnhem, the Netherlands in 1944. The daughters insisted he write it down—"they were very, very persistent". After some delay he began writing in the evenings and completed it 18 months later. The book is dedicated to the two girls.
"To Juliet and Rosamund, remembering the road to Stratford-on-Avon"—Dedication, Watership Down
Adams's descriptions of wild rabbit behaviour were based on The Private Life of the Rabbit (1964), by British naturalist Ronald Lockley. The two later became friends, later embarking upon an Antarctic tour that became the subject of a co-authored book, Voyage Through the Antarctic (A. Lane, 1982).
Watership Down was rejected six times before it was accepted by Rex Collings. The one-man London publisher Collings wrote to an associate, "I've just taken on a novel about rabbits, one of them with extra-sensory perception. Do you think I'm mad?" The associate did call it "a mad risk" in her obituary of Collings; "a book as bizarre by an unknown writer which had been turned down by the major London publishers; but it was also dazzlingly brave and intuitive." Collings had little capital and could not pay an advance but "he got a review copy onto every desk in London that mattered." Adams wrote that it was Collings who gave Watership Down its title. There was a second edition in 1973.
Macmillan USA, then a media giant, published the first U.S. edition in 1974 and a Dutch edition was also published that year by Het Spectrum. According to WorldCat, participating libraries hold copies in 18 languages of translation.