In announcing its decision the Monetary Policy Committee of the Bank of Korea cited low inflation and continued uncertainty over the future of the US Federal Reserve's stimulus programme.
The bank said Asia's fourth largest economy would maintain its uptrend in step with a modest global recovery, with both domestic demand and exports increasing.
But it still sees downside risks such as any volatility caused when the US Fed eventually starts winding down its bond-buying scheme, which has been credited with fuelling an investment splurge in Asia since late last year.
South Korea's economy grew 1.1 percent in the July-September quarter, the same as in the previous three months.
However, inflation is subdued, hitting 0.9 percent in November, slightly up from 0.7 percent in October, while the bank expects price rises to remain tepid for the time being.