Police and the fire department were called to a home north of Qualicum Beach on Monday afternoon.
Two of the three men burned in the fire had to be airlifted to hospital.
Officials have yet to determine the cause of the blaze, but say it appears suspicious.
A house fire Saturday in Ladysmith, about 70 kilometres south of Qualicum Beach, claimed the lives of a man and woman.
The home was engulfed in flames by the time crews arrived and was too dangerous for anyone to enter and attempt a rescue.