Police said officers were called shortly after 8 p.m. Sunday to the Ventura, a music venue located along San Antonio's Museum Reach portion of the River Walk.
San Antonio Police Chief William McManus said an argument broke out inside of the club between a group of individuals and one person pulled out a gun and started shooting.
One victim died at the scene, and another six were transported to a hospital, where one was pronounced dead shortly after arrival.
The victims have not been identified. McManus said the victim who died at the club was male.
McManus said he is confident that a suspect will be soon identified and apprehended. No further information was immediately available.