He's got not one, but two current best-sellers, both set in Afghanistan; "A Thousand Splendid Suns," and his runaway best-selling first novel, "The Kite Runner." But he never actually thought he would be a professional writer.
"I never thought I had the chops to do it," he told CBS News correspondent Thalia Assuras. "I never thought it was, you know, a realistic, viable profession."
This week he's witnessing the nationwide release of the movie version of "The Kite Runner."
"In many ways, it's a first in Hollywood. Because here's a major Hollywood production about a family of Muslims," Hosseini said. "And it doesn't begin with terrorism. It doesn't begin with extremism. It's a human story. It's a family story."
Hosseini says it's his focus on human nature - both loving and cruel - that's captivated millions of American readers, who until a few years ago, had barely even heard of Afghanistan.
It's where Hosseini's own story begins.
"I have vivid memories of growing up in Kabul," he said. "It is so different than what you see on television now. At that time, Kabul was this kind of sprawling cosmopolitan city."
Hosseini's family was well-off in the 1970s. He was the oldest of five children.
"I wouldn't say privileged but certainly comfortable," he said. "My father was a diplomat, worked for the foreign ministry. My mother taught Farsi and history at a very large high school for girls."
And, unlike today, there was no war in Afghanistan.
"I never heard a gunshot in my childhood, I never saw a tank move," Hosseini said. "It was a time when the country was living in a very kind of peaceful anonymity."
When Hosseini was a young teenager, the family moved to Paris. His father was assigned to the Afghan embassy.
"It was supposed to be 3 1/2, four years and we were gonna come back," he said.
"I remember the expression on my parents' faces," Hosseini said. "When they saw the Soviets, I think at that point they realized that, wow, we may never go home again. And we have to start thinking about a new life."
It started in San Jose, Calif., when the family was granted political asylum by the U.S. government.
"Well, this is the first home where we lived," he said while walking Assuras through his old neighborhood. "A three-bedroom house. There were nine of us. We were pretty cramped."
They arrived with only suitcases, so his parents were forced on welfare for a time.
"They'd never been in a position before to be given free money," Hosseini said. "And I think that was shameful to them."
It was hard for Hosseini, too. He was 15 years old and didn't really fit in with the other kids.
"Those first couple of years where really rough," he said. "Because I didn't speak any English and I just did not get the whole high school culture at all."
But he got good grades and eventually became a doctor. It's a classic immigrant success story with two cultures constantly at play.
"This is the largest community of Afghans outside of Afghanistan, Pakistan and Iran. There are maybe 80-90,000 Afghans," he said, referring to his old neighborhood, Fremont, Calif., which is near San Jose.
In Freemont, Hosseini's Afghan roots run deep. A cousin owns a rug store, and dried goods from Afghanistan fill the aisles in a local market where fresh flatbread is baked daily. His two worlds, says Hosseini, fit together easily.
"I rarely think about the Afghan and the American sides as separate parts of my life. It's just kind of become this organic existence."
Yet love was an entirely Afghan affair when Hosseini met his future wife Roya, an Afghan-American, 14 years ago. It was at a party when he was away at medical school. He was smitten within an hour of meeting her.
"I gave her a call five days later, proposed over the phone," Hosseini said. "And she was duly stunned. But I had made an impression on her. And so she accepted. More importantly her father accepted."
He asked his father to seek Roya's hand from her father in the traditional Afghan way. That tradition is played out on scene in what Hosseini says is a favorite sequence in "The Kite Runner," which was originally a short story.
He says he's been writing since he was 8 years old.
"I've always been happiest when I'm kind of indulging the compulsion," Hosseini said. "And it is a compulsion to me. I really wrote all my life until I went to medical school. And then that takes over your whole life."
He only tried to get some of his work published after his wife Roya nudged him a bit. He said portions of the book are autobiographical.
"It's early on especially, he said. "That's the life I loved in those early chapters of 'The Kite Runner.' There's almost this kind of idyllic, romantic feel to those chapters."
But Hosseini's books are far from romantic. Both novels reflect many of Afghanistan's darkest days and the worst of human nature.
"I became what I am today at the age of 12 on a frigid overcast day in the winter of 1975," he writes in "The Kite Runner." "I remember the precise moment, crouching behind a crumbling mud wall, peeking into the alley near the frozen creek. Looking back, I realize I've been peeking into that deserted alley for the last 26 years. I don't want to forget anymore."