The country's tourism account posted a deficit of US$182.5 million in December, according to the data compiled by the Bank of Korea (BOK) and the Korea Culture and Tourism Institute.
The country logged a $206.8 million surplus in tourism in November, the largest level since March 2009.
Officials at the institute attributed the deficit largely to a rise in the number of South Korean tourists going abroad.
The number of South Korean overseas travelers sorared 18.8 percent to 1,430,677 on-year in December, the highest growth in a year, the data said. Meanwhile, foreign tourist arrivals in the country totaled 1,086,569 in number, up 17 percent from a year earlier.