A decree to fine those who engage in "excessive" public exposure passed at a Cabinet meeting presided over by President Park Geun-hye ignited controversy Monday.
The decree is expected to go into effect starting March 22.
People were outraged by the 50,000 won fine, as it brought back memories of similar restrictions on skirt lengths in the 1970s under the rule of the late President Park Chung-hee.
Many netizens criticized the decree as a signal of a return to the authoritarian era.
Social networks services, such as Twitter and Facebook, were buzzing with critical comments ― ranging from who decides the standards of decency to whether the decree will apply to swimming pools and gymnasiums.
"What can I do now if I am fined 50,000 won?" twitted Kwak Hyun-hwa, a 32-year-old female comedian, with a photo of her wearing a sleeveless dress.
Kim Seong-hyun, head of the Progressive Justice Party's Gyeonggi Province office, said, "I am disappointed that the government approved the excessive exposure bill at its first Cabinet meeting at the time of a security crisis. I need a government which I can rely on!"
A female Twitter user said that she hates it when somebody looks at her legs, but would be more upset if police used a tape measure to check out the length of her skirt.
Another netizen posted a photo of President Park wearing a swimming suit, asking whether it violates the law.
The government said that people can be fined if they expose their naked body or expose any part of their body which should otherwise be concealed.
"If their indecent exposure provokes shameful feelings and discomfort to others, they can be fined 50,000 won," said police in a statement.
However, they did not elaborate further on standards of "exposure and the level of shame and discomfort" in detail.