The won was quoted at 1,156.7 to the dollar at the conclusion of onshore trade, down 1.0 percent from Tuesday's close of 1,145.8.
South Korean stocks, however, posted their highest close since early December as foreign investors bought shares, thanks to solid China trade data.
The Korea Composite Stock Price Index (KOSPI) closed up 1.8 percent at 2,015.93.
Foreigners were net buyers, purchasing 552.5 billion won ($478.09 million) worth of shares.