The woman, who was born in 1988, is said to have been raped in the clubs bathroom.
Police received a call shortly before 4.30 Friday morning.
“The woman was taken and driven to Stockholm’s Söder Hospital’s special department for rape victims,” said Joakim Caryll of the Stockholm police.
The bathroom has been blocked off and a technical investigation will be carried out on Friday. The woman has been interviewed about the incident.
“Based on what she’s told us in the interview we will try to track down the perpetrator,” said Caryll.