The Kite Runner was published in 2003 to nearly unanimous praise. Said to be the first novel written in English by an Afghan, the novel was instantly popular. Its first printing was fifty thousand copies, it has been featured on the reading lists of countless book clubs, and foreign rights to the novel have been sold in at least ten countries.

Reviewers admired the novel for its straightforward storytelling, its convincing character studies, and for its startling account of the human toll of the violence that has accompanied Afghanistan's turbulent political scene in the last thirty years. In his review in World Literature Today, Ronny Noor remarks, "This lucidly written and often touching novel gives a vivid picture of not only the Russian atrocities but also those of the Northern Alliance and the Taliban." A brief review in Publishers Weekly credited the novel with providing "an incisive, perceptive examination of recent Afghan history and its ramifications in both America and the Middle East," and called it "a complete work of literature that succeeds in exploring the culture of a previously obscure nation that has become a pivot point in the global politics of the new millennium." The novel was noted for its detailed portrayal of a friendship between two boys that tenuously spans class and ethnic lines. In the New York Times Book Review, Edward Hower praises the novel for its detailed descriptions of life in Kabul in the 1970s: "Hosseini's depiction of pre-revolutionary Afghanistan is rich in warmth and humor but also tense with the friction of different ethnic groups." Hower also notes how the class distinctions between Amir and Hassan make their relationship all the more vulnerable: "Amir is served breakfast every morning by Hassan; then he is driven to school in a shiny Mustang while his friend stays home to clean the house."

A few noted with misgiving that the novel occasionally strays from the conventions of realism in contemporary fiction. Hower notes, "When Amir meets his old nemesis, now a powerful Taliban official, the book descends into some plot twists better suited to a folk tale than a modern novel." Like Hower, Rebecca Stuhr of the Library Journal focuses on the late chapters in pointing out the novel's "over-reliance on coincidence." In an otherwise glowing review in the Times Literary Supplement, James O'Brien points out that "When Hosseini strays from the simple narrative style he prefers, he struggles to retain credibility." Noor argued that the novel gives "a selective, simplistic, even simple-minded picture" of the ongoing Afghan conflict, in particular an overly optimistic view of Hamid Karzai's ability to govern Afghanistan. Overall, reviewers see the novel as a great triumph marred only by rare stylistic flaws.