A search and rescue operation off the northern coast of the island of Lesbos recovered the bodies on Thursday.
The coast guard said 23 people have been rescued.
Reporting on what appeared to be the same sinking, Turkey's state-run media said the incident was attended by the Turkish coast guard after a rubber dinghy sank in the Aegean Sea between the Turkish mainland and Lesbos.
Those rescued were taken to a hospital and the search continued, Anadolu news agency said.
Weather in the area was reported to be good, and it was unclear what had caused the boat to overturn early on Thursday morning.
There was no immediate information on the total number of people who had been on the boat, their nationalities, or the type of vessel they had been using.
A sea and land search and rescue operation was continuing, with three coast guard vessels, an air force helicopter and a nearby boat searching for potential further victims.
Greece is one of the main entry points into the European Union for people fleeing conflict and poverty in the Middle East, Africa and Asia, with many making the short but often treacherous journey from the Turkish coast to nearby Greek islands in inflatable dinghies.
Many are unseaworthy or set out in bad weather, and fatal accidents have been common.
The Greek government has cracked down with increased patrols at sea, and many smuggling rings have shifted their operations south, using larger boats to transport people from the northern coast of Africa to southern Greece.
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