A tremor measuring 4.0 points on the open-ended Richter scale shook a mountainous area northeast of Athens early Sunday, the Athens Observatory's Geodynamic Institute said.
The earthquake, which the institute described as "weak", was recorded at 02:10 am (2310 GMT) in the general area of Mount Penteli, some 13 kilometres (eight miles) northeast of the capital, institute seismologist Anna Fokaefs told AFP.
There were no immediate reports of damage.
The seismologist said the tremor was "unrelated" to a fault line northwest of Athens which in 1999 produced a 5.9-magnitude quake that killed 143 people in the surrounding area.
Greece is more affected by seismic activity than any other European country and bears the brunt of half of all earthquakes on the continent.
