The OECD report released on Friday shows that Korean women were paid an average of 39 percent LESS than Korean men in 2010.
That means Korean women are paid 39 percent less than their male counterparts, much lower than the OECD average of 15 percent.
The next closest country to Korea on the list was Japan, where the wage gap came in at 29 percent.
Korea's income gap has narrowed by just one percent in the past decade.
Experts point to the burden of pregnancy and child rearing as the main reasons for the lower wages paid to Korean women, who often have to restart at lower positions when returning to work.
And there are concerns that the gap may widen even further.
That is because of a shift from manufacturing to the service industry, where jobs are generally less secure because they are usually part-time jobs with low pay.
Among the 28 countries that were surveyed by the OECD, Hungary and Poland had the lowest gender pay gap of 6 percent.
Kim Ji-yeon, Arirang News.