Three youths are suspected of robbing a wheelchair-bound man in Victoria Park in Perth and dumping him onto the pavement before making off with his chair and bag.

WA Police said the thieves, thought to be teenagers, came up behind the 49-year-old man on Leonard Street, just before the intersection of Hodern Street, about 9:30pm on Monday.

He was pushed out of his wheelchair, falling face down onto the footpath.

The thieves ran off down the street pushing the wheelchair, which had the man's backpack attached.

The victim managed to call police, but by the time they arrived the trio had fled.

Police are looking for a woman about 168cm tall with dark skin, slim build, and long black hair. She was wearing blue jeans and a blue and white top.

The young man was described as 188cm tall with dark skin, medium build and short dark hair, wearing a white top.

The third person was described as dark skinned with short wavy brown hair.

Anyone with information is asked to contact Crime Stoppers on 1800 333 000.