A patient undergoing surgery has suffered burns after an electrical fire broke out in an operating theatre at a hospital in Melbourne's north west.

The Metropolitan Fire Brigade (MFB) was called to Sunshine Hospital around 9.20am on Monday, after reports of a fire caused by malfunctioning equipment in one of the surgery suites.

A fire broke out in the operating theatre of Sunshine Hospital on Monday morning. Credit:Fairfax Media

The 72-year-old woman who was injured in the fire has now been taken to a specialist burns unit at The Alfred, where she remains in a critical but stable condition.

The fire was contained to one theatre and no staff were injured. Some non-emergency operations were cancelled at the hospital as a result of the fire.