"We don't know what happened, he was found by a police patrol that was at the location for another matter. It emerged that he had serious knife injuries," Swedish police West region spokesperson Morten Gunnneng told news agency TT.
The man was quickly taken to hospital in critical condition but later died. He had injuries in the abdominal region which police say could have been caused by a sharp weapon.
Police have launched a preliminary investigation into murder and cordoned off the area around Odinsgatan where he was found in order to carry out a forensic investigation. Commuter traffic may be affected.
The man has still to be identified and police were not able to speak with him.