The shooting happened just after midnight at the Sound of Brazil club on Varick Street and West Houston in the West Village and sent panicked clubgoers scrambling for the exits.
Police say it was a shootout between rival gangs, and all the injured people were innocent bystanders.
They were all on hand for a mixtape release party for rapper Fat Trel, who is based out of Washington, D.C. The violence broke out just before the rapper was set to take the stage and perform tracks from his tape.
The shooting is not linked to Fat Trel.
Sources say the dispute was between a gang from New Jersey and another from New York City.
Two people were reported struck in the leg, while the other two were grazed. None of the injuries were believed to be life threatening.
No arrests have been made.