Maureen Shepherd had just got off a bus on the Falls Road at about 7.30 pm on Friday and had turned into an alleyway that leads to Ardmoulin Avenue when the 76-year-old was attacked.
The robber made off with a sum of money and a mobile phone.
Mrs Shepherd was taken to the Ulster Hospital and then moved to the Royal Victoria Hospital where she was treated for a broken jaw and bruising.
Inspector Mark Cavanagh said the next thing she remembered was being on the ground and an unknown teen male standing over her.
During the incident her Nokia phone and a sum of Euros was stolen.
She also sustained a number of facial injuries during her ordeal.
The male involved in the robbery is described as being approximately aged 18 to 19 years old, of thin build and about 5’11” tall.
He was wearing a grey hooded top with the hood pulled up over his head and a black coloured scarf over his face.
Inspector Cavanagh has asked anyone who may have witnessed this incident or who has any information to contact police at Woodbourne PSNI station on the 10 non-emergency number.
Or alternatively information can be given anonymously to Crimestoppers on 0800 555 111.