In the sting operation, police arrested the woman, Jinyu Yuan, 45, and seized "massage tables, a computer, towels and assorted lotions," according to a police news release.
She's charged with prostitution and criminal nuisance.
The case began about a week and a half ago with a tip about suspicious activity at the house, 750 Sunrise Highway, police said. Cops then watched the house and stopped several patrons leaving the massage parlor, police said.
Using the information those patrons provided, along with the surveillance the cops gathered, investigators sought a warrant and sent in the undercover officer, who posed as a customer and visited about 2 p.m.
"We got a feel for what's going on. We sent an undercover officer in, he gets the offer and we made the arrest," said Sgt. Robert Anderson, a supervisor at the West Babylon-based First Precinct's crime section, which investigates misdemeanor cases.
Yuan is to be arraigned Sunday at First District Court in Central Islip.