The general manager of North Canberra Hospital said they are aiming to have the operating theatres damaged in a fire reopened by October.
Workers have cleared all the damaged equipment from the three closed theatres and experts have swabbed the rooms to ensure materials won't cause any infections.
North Canberra general manager Elaine Pretorius said work had now started on re-building the theatres.
"That means that we can now start the building of the last three theatres and the recovery unit is in full [swing]," she said.
"The building company has been fantastic in supporting us with extra shifts on so that we can open those theatres."
The fire occurred when it was operated by Calvary. The ACT government took control of the hospital last month.
There was an electrical fire in an operating theatre at the hospital last December. The fire shut the hospital's seven theatres and the maternity ward for one month.
Three theatres remained closed after they were "significantly damaged" during the fire. The theatres suffered damage due to a combination of fire, water and smoke.
Preliminary investigations have found the cause of the fire was an electrical fault with equipment in the theatre.
Prior to the government acquisition, Health Minister Rachel Stephen-Smith claimed Calvary had stopped repairs on the theatres but Calvary denied this.