Trimeresurus truongsonensis is a venomous pitviper species endemic to Vietnam. Its common names are Truong Son pit viper and Quang Binh pitviper.
This species is known with certainty only from the Phong Nha-Ke Bang National Park, Quang Binh province, in the Annamite Mountains of central Vietnam.
This species is found in evergreen tropical forests at elevations of 500m–600mm (1,600feet–2,000feetm) above sea level. These secretive snakes are mostly seen when basking following strong rains.
Trimeresurus truongsonensis is viviparous.