A man has been taken to Hospital following a fire at Waterloo overnight, NSW Police say.
Emergency services were called to a block of units on Wellington Street shortly after 2am tomorrow.
When police and fire crews arrived, they found a second floor unit well-alight.
A number of residents in the building were evacuated while NSW Fire & Rescue crews extinguished the blaze.
One unit was seriously damaged by the fire.
A 77-year-old man in the building suffered smoke inhalation and was taken by NSW Ambulance Paramedics to Royal Prince Alfred Hospital for treatment.
The cause of the fire has not yet been determined and investigations are continuing.
Police are urging anyone with information in relation to this incident to call Crime Stopers.