The fishermen belonging to Jaffna in the island nation, who had ventured into the sea from Point Pedro on Friday, reached the Vailankanni shore today.
The trio had strayed into India's territorial waters after their boat malfunctioned on Friday night, a Coastal Security Group police said.
When the boat was nearing the shore, it suddenly capsized due to strong winds.
However, the fishermen managed to swim and reach Kameswaram coast early this morning, he said.
Local fishermen rescued and took them to a nearby primary health centre, where the Lankan fishermen are receiving first-aid.
Later, the Q-Branch police and Coastal Security Group police officials took the three fishermen to Keezhaiyur coastal security group police station for enquiry.
Further investigation is on, police said.
The incident comes amid recurring arrests of fishermen from the state by the Lankan naval personnel on charges of poaching fish in their waters.