The Colombo Consumer Price Index, the main measure of inflation in the island, increased by 0.6 percent in February, down from 3.2 percent in January and 4.2 percent a year ago.
The previous low of 0.5 percent was recorded in January 2004.
The new government of President Maithripala Sirisena, who came to power in January, reduced prices of essential food and sharply cut energy prices in line with an electoral pledge.
Deputy Economic Development Minister Harsha de Silva told reporters earlier this week that the government expects inflation to remain low in Sri Lanka this year in line with a global trend.
However, the government is also looking to a $4.0 billion bailout from the International Monetary Fund as it restructures expensive loans taken by the previous government.
The IMF has forecast a growth rate of 6.5 percent for Sri Lanka this year, below the government's target of 7.0 percent.