The 35 year old was walking along Stapleton Road when he was struck on the head by a man who came at him from behind.
He was taken by ambulance to Dumfries and Galloway Royal Infirmary where he was treated and later released.
Sergeant Alan Dillon of Annan Police has appealed for information on the incident which happened around 11 pm.
He stated the man had just left work nearby and was in Stapleton Road when he was attacked.
Two men are understood to have run away from the vicinity and may have gone across a public park in the area.
Sgt Dillon said: “Officers are currently checking CCTV and carrying out door to door enquiries.”
Police ask that anyone who was in the area and may have seen the attack, or who has any other information, contact Annan Police Office on telephone number 101 or Crimestoppers on 0800 555 111.