The move resulted from a telephone plea made by Lebanon's outgoing Prime Minister Najib Mikati with the Syrian authorities, Lebanon's state-run National News Agency (NNA) reported.
The Association of Fishermen in north Lebanon's port city of Tripoli had earlier said Syrian authorities had promised to release the nine fishermen and return them home with their four boats, the Beirut media reported.
They were interrogated by the prosecutor general of Syria's northern port city of Tartous before their release.
Tripoli fishermen say they have been fishing for decades at the Lebanese-Syria coast stretch of Tripoli-Arida before Syria's sudden enforcement of a sea blockade to back its trade war that started with the closure of Syria's land borders with Lebanon over the past three weeks.
They say hundreds of Syrian fishermen have long been making their living form fishing in Tripoli waters unmolested.