The Muslim prayer room at the University of Sydney has been trashed, with an abusive note left at the scene.

The Sydney University Muslim Students' Association says it is the fifth time in three months that the prayer room has been targeted by vandals and thieves.

The Islamic prayer room at Sydney Uni has been trashed Credit:Islamophobia Watch Australia

The association's spokesman Shahad Nomani said a student at the university had discovered the ransacked room about 10am on Monday.

"She walked in and found the cupboard open and all the things thrown down on the floor. I think some money was also stolen from the donation box and a note was left on the table," Mr Nomani said.