According to the Waller County Sheriff's Office, the deputy was driving on Garrett Road at Robichaux around 2am, heading to a disturbance call, when his vehicle hit a 27-year-old man.
Officials said the man was associated with the reported disturbance and had been drinking alcohol before the accident. They believe he fell asleep in the roadway.
Authorities said the deputy was traveling less than 20mph and did not see him.
The man was flown to the hospital but died from his injuries. He has not been identified.
Take ABC13 with you!
Download our free apps for iPhone, iPad, Android and Blackberry devices