A group of about 10 hooded assailants stormed a class at the University of Piraeus on Thursday and threw paint at the lecturer.
The incident occurred during a lecture by Professor Mary Bosi at the Department of International Studies.
The hooded assailants disappeared.
Bosi sought to downplay the attack saying that it was a minor incident and should not be exaggerated.
However, the governing SYRIZA party issued a statement condemning the attack and claiming that such incidents “undermine the public nature of education and pave the way to authoritarianism”.
Incidents of violent attacks and vandalism at Greek universities are common, with critics claiming the government is turning a blind eye to leftist and anarchist extremists.