A window was smashed at the Station Hotel in Insch overnight between Monday and Tuesday.
A container of petrol and a length of rag were later discovered.
No-one was injured. The petrol failed to ignite as part of the suspected attack.
Police have launched a probe into the incident.
On their Facebook page, the hotel owners described the incident as “a sickening criminal act”.
They claimed a five-litre container full of fuel with a cloth tied around the handle had been thrown into the building.
Any witnesses have been urged to contact police. A “substantial” reward has been offered.