The third person involved in the incident was released because it was not proved that she had taken part in the offence.
The three students were heard at Zagreb's Magistrate's Court today.
Stevan Vranesevic was sentenced to 15 and Mirjana Djerkovic to five days in jail, while Danja Bozanic was acquitted, said Judge Damir Romstein.
The two will serve their sentences at Remetinec prison. They may lodge appeals with the Senior Magistrate's Court in Zagreb.
Representatives of the Serbia and Montenegro Embassy attended today's hearing.
The three students arrived in Zagreb yesterday as part of a group of some 300 students from Belgrade who came to see the "Dora Maar and Picasso" exhibition. At one moment, they separated from the group and photographed themselves showing a picture of Mihailovic. Some disgruntled citizens who saw this reported them to the police, after which the three students were arrested.