The gruesome discovery was made around 5 p.m. on Wednesday in the 25500 block of White Oak Lane in Splendora.
Deputies said the man arrived at his ex-wife's house to drop off their 8- and 12-year-old children when they found her in the garage. That's when he called 911.
Deputies said the woman, who was identified as 41-year-old Holly Vines, had been shot to death.
Authorities said they are investigating the incident and trying to piece together what happened.
They have not identified a suspect.