Around 150 police officers raided the bar called "Rain" on Le Hong Phong Street. When the police entered, around 300 patrons who were dancing to loud music threw drugs on the floor and tried to escape, but the exit doors had been blocked.
Of more than 300 people taken to the police station for drug tests, 92, including five employees of the bar, tested positive for banned substances, but the police did not specify what they were.
Rain, considered the largest and busiest bar in Da Lat, a popular resort town in the Central Highlands, attracts many patrons at night, especially during holidays and weekends.
Vietnam has very strict laws against the production, trafficking and distribution of drugs, including the death penalty, but this has not stopped any of these activities as also the consumption of banned substances.
Vietnamese police have recently intensified their crackdown on drug abuse at nightclubs and karaoke parlors across the country.
A pre-dawn police raid on a bar inside a five-star hotel in southern Dong Nai Province last December found 88 customers aged between 18 and 30 using banned drugs.