A naval craft picked up the Sri Lankans, including 17 women and 14 children, who had been drifting for days off the island's southwest coast following engine trouble in their fishing trawler, a naval official said.
"The navy responded to a distress message sent out on Thursday and the passengers were rescued, and brought ashore on Friday," the official told reporters at the southern port of Galle.
Navy spokesman Kosala Warnakulasuriya confirmed the rescue mounted Thursday and said investigations were underway.
One of the passengers told reporters he had paid more than ,000 to people-smugglers who had promised to take him and his fellow passengers to Australia within two to three weeks.
It is the first report of a fresh load of boatpeople illegally leaving Sri Lanka since Australia's previous government in mid-July announced tough measures to curb asylum-seekers.
Australia's new Prime Minister Tony Abbott has said he will act swiftly to implement a central plank of his election