Police are appealing for assistance to identify a man responsible for an armed robbery on a pharmacy in Port Melbourne on Wednesday.

The man entered the Bay Street Pharmacy at 2pm armed with a firearm.

The male approached the front counter and demanded money from two staff members.

Nobody was injured during the robbery and the offender ran north on Bay Street.

He is described as Caucasian, aged between 30 and 40, approximately 180cm tall, thin build, brown shoulder length wavy hair, acne and a patchy beard with hollowed cheeks.

He was wearing a black baseball cap, dark blue parachute tracksuit pants a blue tracksuit top, white runners and black gloves.

Investigators have released an image of a man that may assist with their enquiries.