The incident occurred around 12:30 a.m. Sunday outside the Encore Bar near the intersection of 40th Street and Girard Avenue.
Police say two men got into an argument inside of the bar leading to an altercation outside.
According to authorities, one of the males pulled out a knife and stabbed the other multiple times, twice in his left side and twice in his lower back.
The victim, a 28-year-old male, was rushed to the Hospital of the University of Pennsylvania in critical condition.
The suspect remains on the loose.