Another eight face similar charges, police said.
The suspects, 13 Greeks and two foreigners, are aged between 18 and 69 years old. The eight were arrested after coordinated searches in Attica, Thessaloniki, Rodopi, Iraklio and Hania.
Suspects had allegedly been using the Internet and communicating over social media and via chat rooms in order to obtain and exchange child pornography.
Police said they often used the material to blackmail their victims into sex.