The two dead rangers from Thung Yai Naresuan Wildlife Sanctuary were identified as Boonsilp Intapanya and Arnthong Ngamying.
They exchanged gunfire with a group of illegal hunters believed to be from the Hmong ethnic minority. Two other forest rangers were wounded while one poacher was killed during the fight.
Border patrol police have been dispatched to the forest to hunt for the remaining four poachers who escape from the shooting scene.
The incident occurred late last night after the foresters were notified by their counterparts of nearby Huaikhakhaeng Wildlife Sanctuary in Uthai Thani province that a group of illegal hunters were believed to have fled arrest into the Tak forest after they shot bears in Huaikhakaeng.