Norton Shores police responded to Mibar, 2389 W. Sherman, after the 2 a.m. disturbance, according to Lt. Jon Gale.
Witnesses said one man approached another on the patio and later attacked him with a knife, stabbing him three times.
A bar employee who attempted to break up the fight was also stabbed multiple times, Gale said.
The victims were taken by ambulance to Hackley Hospital in Muskegon. One man received stitches and was released. The other man is still hospitalized with an abdominal wound.
The suspect is a white male, approximately 30 years old, 5 feet, 10 inches, with a skinny build, short hair, goatee and a cross tattoo on his back.
Anyone with information on this incident should call Silent Observer at 231-722-7463 or Norton Shores Police Department at 231-733-2691.