"AEK FC announces the termination by mutual consent of the contract of the club's coach Mr Giorgos Donis," the club said in a statement on their offical website.
The 39-year-old Donis joined AEK after four years in charge of Larissa, during which time he won the Greek Cup.
Since an opening day win over Panathinaikos in the Super League, AEK have struggled for form this season and have won just two more league games.
They are fifth in the standings, eight points behind leaders Olympiakos Piraeus.
AEK also made an early exit from the UEFA Cup, beaten by Cypriot side Omonia Nicosia.
