The 24-year-old victim was attacked from behind by two thugs on Saturday morning - one pinning his arms back while an accomplice rifled through his pockets before making off with a small sum of cash.
Police say the man has been left "extremely distressed" by the attack which took place on Ferry Road at 11.30am and are urging members of the public to come forward with information.
News of the mugging comes days after a pensioner was targeted at a cashpoint opposite a post office on Morningside Road.
The legs of the 73-year-old man were kicked out from under him before the assailant snatched money from his hand while he was on the ground. Detective Sergeant Bill Barclay described the most recent incident as a "despicable" attack.
"The complainer, who looked young for his age, was in a vulnerable position and was taken advantage of by two men as he had left the post office after attending to some business there," he said.
"It was quite early in the day for an attack like this to take place but that's the way of the world.
"If the opportunity is there (some people] will take it. It seems the young man was in the wrong place at the wrong time. These people can strike at any time and people are urged to be vigilant."
Mr Barclay said police couldn't rule out the possibility the duo had been stalking the area for potential victims prior to the attack but added that elderly residents shouldn't be alarmed.
"I can't say that's not a possibility but I don't want to put elderly or vulnerable people using the post office in a state of fear. There's a chance they have seen the young guy and decided to take advantage," he said.
Police would be investigating to determine whether this attack could be linked with other similar incidents around Edinburgh, Mr Barclay added.
The first suspect is described as being a white male in his early 20s, 5ft 11in tall with a slim build and short brown hair that was brushed forward.
He was wearing a grey top with yellow Adidas stripes as well as black Adidas tracksuit bottoms.
The second suspect is described as white, in his early 20s, 5ft 11ins tall with a slim build and short black hair.
He was wearing a blue hooded top and blue trousers.
A police spokesman said: "Neither suspect spoke to the complainer or made any threats, but their actions during the robbery left him extremely distressed.
"Anyone who believes they may have seen anything suspicious on Ferry Road around 11.30am on Saturday is asked to contact police immediately.
"Similarly, we would be keen to speak with anyone who recognises the description of the suspects and can assist in identifying them."
Anyone with information should contact Lothian and Borders Police on 0131-311 3131, or Crimestoppers on 0800 555 111.