The BBC described the conversation as "warm and friendly."
Zapatero, a socialist opposed to the war in Iraq, won power Sunday in the wake of last week's Madrid terror attacks, which left 200 dead and 1,500 injured.
The new Spanish leader may withdraw Spain's 1,300 troops stationed in the Gulf region.
The British House of Commons Monday observed a two-minute silence in memory of those killed in the Madrid bombings.
Blair enjoyed close relationship with Zapatero's predecessor, Jose Maria Aznar who supported the invasion of Iraq.
The new socialist leader has already attacked the United States and Britain, saying the leaders of the two countries need to engage in some self-criticism in the wake of the war,which he described as a "big disaster," the BBC said.