The police, attached to the Anti-Human-Trafficking Division, raided four karaoke lounges in Suphanburi province's Songpeenong district in the wee hours to rescue the young Lao girls, aged between 13 and 20 years, Xinhua reported.
The raid was conducted following tip-offs from villagers that the girls had been lured and forced by suspected human traffickers into flesh trade over the past several months, the report said.
The karaoke lounge keepers had allegedly told the Lao girls that they would be hired as "waitresses".
But they had eventually been forced into prostitution, police said.
Several Thais, including the lounge keepers, were arrested on charges of human trafficking while the rescued girls were yet to be returned to their home country, police said.
The Thai authorities earlier pledged to combat human traffickers, including those who may have brought young females from neighbouring countries such as Laos and Myanmar for flesh trade in the Thai capital, outlying areas and the provinces.