Two Tulsa Housing Authority security guards called police after finding a man dead on the side of a street late Monday.
It happened at 11:20 p.m. Monday in the 800 block of East Apache.
The security guards found the man face down near a curb.
The state Medical Examiner's Office now has the man's body.
Tulsa Police say the man didn't appear to have been hit by a car or truck so they are treating it as an unattended death.
"Full autopsy might reveal something else, but at this time it does not look like there was any other kind of foul play or criminal act involved," said Tulsa Police Cpl. Brandon Disney.
Police have notified the family, but have not released the victim's name.