Atmatzidis was born on April 24, 1969 in Kozani, Macedonia, Greece. He played for Pontioi Veria until 1992 when he made the big jump to AEK where he quickly became a regular. With AEK, he won 2 championships and 4 Greek Cups. Late in his career (2002) he transferred to PAOK. He stopped playing in 2005.