A smoker was taken to hospital with burns on his hands, after setting fire to bedding at the Islesburgh hostel.
At 2.10am on Wednesday a small fire broke out in one of the rooms.
The man is thought to have caused the fire while he was smoking a cigarette in one of the bedrooms, setting alight the bedclothes.
He was able to put the fire out, but not before the smoke detector and fire alarm went off.
The man was the sole guest in the hostel and the overnight duty manager helped him from the building.
Two fire engines from Lerwick went to the scene and police also attended.
There has been some fire damage to the bed, mattress and floor but the hostel remains open.
Hostel manager Dale Smith, said: “We obviously have strict fire procedures in place that were swiftly put into place by our overnight staff member last night [Wednesday].
“I am pleased that it was a quiet night in the hostel and that the damage is confined to just one room. We do remind all our residents that smoking is prohibited in Islesburgh and will continue to do so in future.”