The victim – a 34-year-old woman – was approached by a man while walking in Oxgangs Road North at around 11pm yesterday.
A struggle ensued after the man tried to grab the woman’s rucksack close to Oxgangs police station and a chip shop.
The woman, who refused to let the handbag go, was knocked to the ground but her assailant was forced to run off empty-handed after a female passer-by began shouting.
The suspect is described as white, six feet tall and with a slim build. He was wearing a grey, hooded top and jeans..
Pc Sandie Chester said: “We have not yet traced the woman who intervened so we would appeal to her to contact police.
“We are appealing to anyone who saw this man in the area to come forward.”
The front desk at Oxgangs police station had closed to the public at 8pm, but officers are still stationed from the building outside those hours.