Police are asking anyone that witnessed a fire at the old Mooroopna hospital on Thursday, January 27, to come forward.
Shepparton police Detective Senior Constable Andrew Costello said the blaze started at the McLennan St site about 8.30pm.
Two palm trees near the building were burnt before the fire was contained, Det Sen Constable Costello said.
The fire was extinguished before the building caught alight.
Police are investigating the cause of the fire, and are treating it as suspicious.
Anyone who witnessed the fire or has information or dash-cam footage of the incident is asked to contact Shepparton police on 5820 5777 or call Crime Stoppers on 1800 333 000.
You can also submit a confidential report at www.crimestoppersvic.com.au