In 2012, South Korea's gross domestic product was up 2 percent year-on-year.
The Bank of Korea on its web site said last year's fourth quarter GDP grew 0.9 percent from the earlier quarter, or slower than the 1.1 percent quarter-to-quarter growth in the third quarter. But the fourth quarter figure was up 3.9 percent from the same quarter of last year.
South Korea's economy is Asia's fourth largest, after that of China, Japan and India.
The central bank said last year's growth was led by strong exports, which account for about half of the country's GDP, and rising private spending. Exports rose 2 percent in the fourth quarter from the previous three months, after falling 1.3 percent in the third quarter.
Speaking to reporters, Jung Young-taek, the head of the bank's economic statistics division, blamed the fourth quarter results on decline in government spending caused by a fall in tax revenue, Yonhap News reported.
He said it remained to be seen whether capital investment would maintain its growth, the report said.
Economic growth in the bank's estimate is forecast at 3.8 percent for this year. Inflation outlook was reduced to 2.3 percent for 2014 from the earlier estimate of 2.5 percent. The key interest rate remains unchanged at 2.5 percent.