Greek authorities say, reports Al Jazeera.
The coast guard said the accident occurred early on Wednesday when a wooden boat carrying the refugees from Turkey sank near the islet of Farmakonisi.
At least 26 people have been rescued alive.
The dead were five children, four men and two women. Their nationalities were not immediately known.
The latest incident happened just a day after six Afghan children drowned off the coast of the western Turkish province of Izmir, as the rubber dinghy they were in sank before reaching the Greek island of Chios.
Greece is the main entry point for refugees seeking a better life in the European Union.
More than 600,000 people have arrived in Greece this year by making the short but perilous journey by boat or rubber dinghy from Turkey to outlying islands. Thousands more have drowned.