The Department of Public Safety says the accident happened around 1 a.m. Tuesday about 10 miles north of Raymondville on southbound U.S. 77.
Sgt. Johnny Hernandez says the vehicle went off the road, the driver over-corrected and the SUV rolled several times. The four people who died were not wearing seat belts and were ejected from the truck.
The accident killed 30-year-old Patricia Castro of Mercedes, 35-year-old Jason Anthony Mayhood of Brownsville, 20-year-old Enrique Rodriguez of Edcouch and 47-year-old Sanricardo Ramirez of Harlingen.
Officials say a 3-year-old girl and a man were hospitalized. The driver and another man were treated and released.