The government says it will make the changes at seven regional hospitals.
The hospitals are in Yarmouth, Kentville, Bridgewater, Truro, New Glasgow, Antigonish and Sydney.
Health Minister Leo Glavine says the government will spend $9.7 million on the conversion projects.
He says converted hospitals will be able to switch between natural gas and oil, depending on which is most cost-effective at any given time.
Four hospitals in the province are already using natural gas.