Michael Jadric's victim needed 42 stitches in his face and head, and may still need more surgery to mask the lasting damage.

Jadric was yesterday sentenced in the ACT Supreme Court after pleading guilty to assault occasioning actual bodily harm.

Justice John Burns said Jadric's crime warranted a custodial sentence, but that the 19-year-old's youth and good prospects of rehabilitation entitled him to a second chance.

He sentenced him to 15 months, suspended on entering a two-year good-behaviour order.

In February this year, without provocation, Jadric smashed an empty beer bottle over the head of a complete stranger outside a Ngunnawal house party.

His victim needed surgery under anaesthetic to remove shards of glass from the wounds.

''The scars that your victim now bears are very visible and cause him a great degree of stress and anxiety,'' Justice Burns said.

''It is possible that he will require further surgery in order to ameliorate the obviousness of that scarring.''

The judge said such treatment was likely to come at considerable financial expense.

''More importantly these scars are a constant reminder to the victim of what you did to him, so that he can't put this behind him,'' he said.

The court heard Jadric was drunk at the time of the assault, and had no memory of the glassing. But he pleaded guilty after his legal team received a copy of the brief of evidence against him.

The judge noted Jadric had taken steps to cut down his drinking in the aftermath of the crime.

Justice Burns accepted Jadric was a low-risk of reoffending if he could control his drinking.

''Mr Jadric, you've come very close to going to prison with respect of these matters,'' he said.

''I think it's pretty obvious that if there are other offences of violence in the near future you will go to prison.''