Four gas cylinders have been stolen from Victoria Hospital.
They were taken from the dental unit overnight on Wednesday.
Moving the cylinders, which contain nitrous oxide, would have required a vehicle.
Police have appealed for witnesses.
Confirming the overnight break-in Constable Sean Frew from Kirkcaldy Police Station said: “At this time we do not know if the cylinders have been stolen for resale purposes or for whoever took them to abuse the nitrous oxide within them.
“However, the cylinders themselves are quite cumbersome and heavy to move, meaning a vehicle was likely used during their theft.
“With that in mind anyone who remembers seeing a suspicious vehicle around the hospital on either Wednesday evening or the early hours of Thursday morning should contact us immediately.’’
Call Police Scotland on 101 or alternatively, the charity Crimestoppers on 0800 555 111.