Bush ducked, and the shoes, flung one at a time, sailed past his head during the news conference with Prime Minister Nuri al-Maliki in his palace in the heavily fortified Green Zone.
The shoe thrower identified as Muntadhar al-Zaidi, an Iraqi journalist with Egypt-based al-Baghdadia television network could be heard yelling in Arabic: "This is a farewell ... you dog!"
While pinned on the ground by security personnel, he screamed: "You killed the Iraqis!"
Al-Zaidi was dragged away. While al-Zaidi was still screaming in another room, Bush said: "That was a size 10 shoe he threw at me, you may want to know."
Hurling shoes at someone, or sitting so that the bottom of a shoe faces another person, is considered an insult among Muslims.
Al-Baghdadia issued a statement demanding al-Zaidi's release. Al-Zaidi remained in custody, while the Iraqi judiciary decides whether he will face charges of assaulting al-Maliki, a government official said.
The official said al-Zaidi is being tested for alcohol and drugs to determine if he was fully conscious during the incident.
Al-Zaidi drew international attention in November 2007 when he was kidnapped while on his way to work in central Baghdad. He was released three days later.
Bush had been lauding the conclusion of a security pact with Iraq as journalists looked on.
"So what if the guy threw his shoe at me?" Bush told a reporter in response to a question about the incident.
"Let me talk about the guy throwing his shoe. It's one way to gain attention. It's like going to a political rally and having people yell at you. It's like driving down the street and having people not gesturing with all five fingers.
"These journalists here were very apologetic. They said this doesn't represent the Iraqi people, but that's what happens in free societies where people try to draw attention to themselves."
