It happened around 4:30am on Old Atascocita Road.
Police say a BNSF freight train was passing the road when the conductor spotted the man standing on the tracks and couldn't stop in time.
Investigators are still on the scene trying to identify the victim and figure out why he was on the tracks.
At last check, Old Atascocita Road was closed in both directions.
Please stay with Eyewitness News and abc13.com for updates.