A frail, elderly woman has been hospitalised after allegedly being smashed on the head with a beer bottle in East Perth overnight.

The 79-year-old victim was watering in the communal garden area of an apartment complex on Goderich Street at about 6.15pm when she was approached by a 47-year-old woman.

Police will allege the 47-year-old abused the victim before striking her head with a beer bottle, causing a deep cut behind her ear.

The victim fell to the ground and the police will further allege the 47-year-old then punched her repeatedly in the head.

The 79-year-old was taken to Royal Perth Hospital.

The 47-year-old woman has been charged with assault and trespassing and will appear in the Perth Magistrate’s Court today.