A 23-year-old man was shot in the leg at 'The Jungle' in Mainland City Centre at about 1:30 a.m.
Texas City police were already on the way to the club because of reports of a large crowd, according to Sgt. Allen Bjerke.
"When officers arrived, people were flooding out of the club," Bjerke said.
Investigators said they found several shell casings at the scene.
The 23-year-old was taken to HCA Houston Clear Lake Houston by ground ambulance and is expected to be OK.
No one was taken into custody as of 3 a.m.
The Jungle boasts of customers being able to release their "inner animal." The Houston events group, We Own the Night (WON) Media and Marketing, operates them. WON sets up adult-themed pool parties and events at nightclubs and bars in the Houston area.
Anyone with information on the suspect is urged to contact Crime Stoppers at 713-222-TIPS (8477), submitting an online tip or through the Crime Stoppers mobile app.