Hanover Police say the Hospital received the threat just before 10:30pm last night and as a precaution the building was evacuated and a search was conducted.
Joining police on site was the Hanover Fire Department and Grey County Paramedics.
The search turned up nothing suspicious at the site.
There is a criminal investigation underway and the police say they have a person of interest that was seen around the hospital in a dark coloured vehicle.
If anyone has information regarding this incident they are asked to call the Hanover Police at 519-364-2411 or Crime Stoppers anonymously at 1-888-222-8477.