Police said the incident began just after 10 p.m. when a fight broke out on the Boardwalk in the area of Wilmington Avenue.
According to investigators, a man wearing a gray New Balance Sweatshirt, gray sweatpants, a backpack and dark colored sneakers approached the victim. He took a knife out his pocket and stabbed the victim in his left side.
Police said the suspect and three others then ran west on Wilmington Avenue.
The victim was taken to a nearby hospital where he remains in stable condition.
Police have released photos of the alleged incident.
The first photo shows the suspect and his two alleged accomplices.
The second image shows the alleged stabbing incident.
Anyone who might have seen the incident take place or who knows the individuals depicted in the photos is asked to contact Rehoboth Beach police at 302-524-1391.
Anyone having contact with the suspect is asked to immediately call 911.