A passenger ferry carrying over a thousand people arrived at the port of Piraeaus after being on fire earlier.
More than a thousand people were on board, on route to Chania in Crete when it was forced to return.
There were no immediate reports of injuries, according to the coast guard.
The vessel was escorted by air and sea rescue with fire engines at the port to tackle the blaze.
The ship was continually doused with water from rescue boats.
This footage was taken by a passenger and you can see how much smoke filled the air.
From the shore, you can see the black smoke billowing.
It's thought the fire was started from a vehicle but it's still not clear until an investigation is carried out.
Around 200 vehicles, including trucks, were parked on board.
Passengers wearing life jackets disembarked safely after a huge operation, according to a coastguard spokesperson.