Around 1pm on Saturday June 7, the woman had been at the Airdrie Sports Centre.
She left the centre and was walking down Waverly Drive when a group of youths assaulted her and hit her with a bottle.
She sustained serious lacerations to her face and was taken to Monklands Hospital.
She has since been released following treatment.
Police are keen to speak to anyone who was in the area at the time and are currently gathering and reviewing CCTV images in an effort to gain further information about the suspects and the incident.
The five youths are described as white, between 15 and 16 years old.
One was wearing a white t-shirt and had dirty blonde hair.
A second was wearing yellow shorts and had brown hair.
The third was wearing peach coloured shorts with fair hair and the fourth was wearing a dark coloured top.
Inquiries so far have revealed that the group of youths were hanging around the Sports Centre so will have been seen by people leaving and entering the sports arena.
Detective Sergeant Kenny Dalrymple said: "This assault was entirely unprovoked and has left a young woman with serious facial injuries.
"I am sure local people will know who these young men are and I am appealing to them to contact us - if you were at the sports centre on Saturday morning, perhaps you noticed this group of youths, if so, please contact us as a matter of urgency.
"Any small piece of information could aid the investigation and help us trace those responsible for this violent attack."
Anyone with information is asked to contact Coatbridge Police Office on the police non-emergency number, 101. Alternatively they can call Crimestoppers anonymously on 0800 555 111.