The incident, which happened in broad daylight near a busy high street in Essex, is being treated as a hate crime.
The pair was approached in the early afternoon by the man, who pulled out what appeared to be a black handgun before hurling insults.
An Essex Police spokesman said: “Two Polish men were approached by a man in a mobility scooter who was reported to have produced what has been described as a black handgun.
“It was reported that the man in the mobility scooter, which was believed to be red with a black basket on the front, then pointed the handgun at one of the men and shouted a racially aggravated insult.
“He then made off in the direction of Southend High Street."
The man is described as white and clean shaven with a bald head. He was wearing a dark top and blue jeans.
He is believed to be in his 50s, of medium build and around 6ft tall.
Detectives are appealing for information following the incident in Queensway, Southend, just before 1pm on Saturday, April 15.
Anyone with information is asked to contact DC Mike Buckingham at Southend CID on 101 or Crimestoppers on 0800 555 111.