The three men, who had been arrested several times in the past for their involvement in drug peddling, were detained under the PSA yesterday, police said today.
The Act allows the authorities to detain a person for up to six months without trial.
The three have been identified as Fayaz Ahmad Dar, Bilal Ahmad Sofi and Mohammad Amin Najar, all residents of Baramulla district.
They were involved in a number of cases and were supplying drugs to school students and youth in the north Kashmir town, police said.