Assad, dressed in a dark suit and sitting in the front row, joined men praying at Al-Afram mosque to celebrate the Prophet Mohammad's (PBUH) birthday, according to the footage broadcast.
Assad has appeared several times recently, including on Dec. 31 when he was reported to have visited Syrian troops northeast of Damascus in what was presented as a morale-boosting trip at New Year.
Damascus city is under government control but pro-government forces regularly clash with armed terrorists on the outskirts.
After Sunday's prayers, Assad shook hands and embraced clerics and other worshippers at the mosque, the footage showed. He prayed at the same mosque last year for the celebration, according to Syrian media reports.
In October he took part in prayers marking the Eid holiday in the capital and in July he appeared at the presidential palace when sworn in for a new term vowing to recover all of the country from terrorists.