 During the summer of 2006, Mavrokefalidis was signed by Virtus Roma of the Italian League and EuroLeague, but he was not established as a key member of the team, averaging just 2 points and 1 rebound per game.In February 2007, he was transferred from Roma to Pamesa Valencia of the Spanish ACB League, in exchange for Roberto Chiacig and Jon Stefánsson.On July 12, 2007, Mavrokefalidis joined Olympiacos.