The Teranet-National Bank National Composite House Price Index measured resale prices in Ottawa, Toronto, Calgary, Vancouver, Montreal and Halifax.
It found the biggest gains were in Vancouver, where prices rose 17.1 per cent, and Toronto, where they are up 16.0 per cent.
The 12-month rise ranged from 5.6 per cent in Halifax to 11.4 per cent in Ottawa. In Calgary, it was 7.8 per cent and in Montreal, 8.5 per cent.
And for the second consecutive month, prices rose in May over April in all six metropolitan areas surveyed.