The US publication of Life of Pi in mid-2002 was preceded by its publication in Canada in 2001 and the United Kingdom in early 2002. In Great Britain, the Daily Telegraph (London) criticized it as a novel that “never really comes alive in the emotional sense” due to its concern with pursuing “a series of narrative questions and solutions.” Nonetheless, it praised Martel’s book as a “hilarious novel, full of clever tricks, amusing asides and grand originality.” The London Observer echoed this praise in saying that “Martel has large amounts of intellectual fun with outrageous fable” as he creates a book that “dramatises and articulates the possibilities of storytelling.” The Guardian continued this theme of praise for the book’s fantastic nature by calling it “an edge-of-seat adventure” and an “enormously lovable novel . . . suffused with wonder.” However, the reviewer slightly tempered this sense of fantasy by noting that Martel’s narrator “has a believer's scepticism about reason.”

In the United States, reviews continued to effusively praise Life of Pi with an emphasis on its magical qualities, humor, and meticulous creation of a believable yet fantastic story. Salon.com said that although the novel’s premise “might sound ridiculous,” that “by the time Martel throws Pi out to sea, his quirkily magical and often hilarious vision has already taken hold.” Pi, the reviewer wrote, has a "nonreligious kind of understanding and faith.” Publishers Weekly said Martel takes the reader on “a fabulous romp through an imagination by turns ecstatic, cunning, despairing and resilient.” The New York Times observed that as a zookeeper’s son, Pi is “attuned to the intricacies of interspecies cohabitation,” and he uses this knowledge to gain power over the tiger who accompanies him and thereby keep himself alive. The reviewer further claimed that since Pi is “a practitioner of three major religions who also happens to have a strong background in science,” his “story inevitably takes on the quality of a parable.” Martel’s book, the review continued, “could renew your faith in the ability of novelists to invest even the most outrageous scenario with plausible life.”

Not all critics were so impressed. The Boston Globe said that its “deadpan seriousness . . . can grow wearisome” while Pi discusses his three religions and that when finishing the book, it is “hard not to bristle with the skepticism that comes from having weathered a hard sell for the Lord.” The reviewer went on to say that the novel is most successful when it is both “serious and silly at the same time.” In assessing its balancing of fantasy and precision, many critics professed their delight in Life of Pi by discussing the fairly straightforward narrative of Pi’s journey that he tells to two researchers when he lands in Mexico. Salon.com said that “this played-down version makes Pi’s true tale, thanks to Martel’s beautifully fantastical and spirited rendering, all the more tempting to believe.” The New York Times said “it’s a testimony to Martel’s achievement that few readers will be tempted to think” that the more straightforward narrative is more honest than the fantastic one.