They found many plastic bags containing white crystals looking like meth on the tables and floors of the Gossip Karaoke parlor.
Over 100 men and women were taken in for questioning and 96 tested positive for banned drugs.
The parlor owner, 39-year-old Tran Van Dai, was also in the news last February, when a bar that he owns in the same province was raided and 94 people, including 20 women, tested positive for drug use.
Both the karaoke and the bar are locally known as "heavens for players (drug users)" in Ca Mau.
Many reports have noted that while heroin has long been common among drug users in Vietnam, the use of synthetic drugs like meth or ecstasy has been rising of late, especially among the partying youth.
Last September, seven people died of suspected overdose at a music concert in Hanoi.
Last month, a drug bust found 300 kilos of meth in Ho Chi Minh City. The people involved were part of gang that was busted with almost a ton of meth in three different raids.