The attack happened in Cwmfelinfach, near Blackwood, on Tuesday April 20 at about 9.40am.
The local woman was walking along a path that runs behind Penllwyn Street towards Nine Mile Point Industrial Estate when she was approached by two men.
One of the men asked her for a cigarette and when she said she didn’t have one he pushed her to the ground and the other man searched her pockets.
An elderly man walking his dog nearby came over and intervened and the two men ran off. The victim sustained no injuries.
Police are keen to speak to the dog walker because he may be able to provide further information that could assist enquiries. He is described as being in his mid-to-late 70s, was wearing a dark coat and was walking a large black dog.
The two men, aged 18 and 21, have been arrested on suspicion of attempted robbery and released on police bail.
The dog walker, or anyone with information about this incident, should contact Gwent Police on 101 or Crimestoppers anonymously on 0800 555 111.