The fire Thursday also forced the evacuation of medical clinics and a summer camp. Gale force winds fanned on the flames on Mount Penteli, hampering firefighters and preventing water-dropping aircraft from reaching the scene for nearly two hours.
More than 300 firemen, assisted by the aircraft and volunteers eventually extinguished the major fronts of the blaze and remained on alert in case winds rekindled it, a fire brigade spokeswoman said.
The fire quickly swept through tinder-dry pine forest, burning at least 25 homes in the capital's affluent northern suburbs.
Officials have yet to establish the cause of the blaze, but state NET television said experts were investigating residents' reports of arson.
Many of the forest fires that strike Greece every summer are attributed to arsonists seeking to develop prime land.
The full extent of the damage was still unclear Friday. The three affected districts — Nea Penteli, Melissia and Kifissia — were declared in a state of emergency.