"Gorbachev has been in the Grosshadern clinic at Munich University for examination and treatment related to his right internal carotid artery since November 19, 2006," the foundation, an independent socioeconomic and political think-tank that the politician set up following his resignation, said on its Web site.
Gorbachev, 75, was operated on November 21 and is now feeling fine, said representatives of the organization.
The last Soviet leader had organized and was expected to attend the seventh international conference of Nobel Peace Prize winners in Rome November 17. The meeting was to focus on nuclear technologies.
But the charismatic leader chose to follow his doctors' advice and canceled the trip to undergo a medical examination, Vladimir Polyakov of the Gorbachev Foundation press service said.