It happened around 2:30am on Highway 35 near Walnut. Officers tell Eyewitness News a woman was walking on the tracks and the train operator wasn't able to stop in time. The victim in her 30s hasn't been identified.
The train conductor and an engineer onboard were not injured in the accident.
Pearland authorities say they are now investigating this incident as a suicide.
Police had temporarily blocked off FM 518, Orange, and Walnut at Highway 35 due to the investigation for several hours. All roadways have since reopened.