Lachesis stenophrys, commonly called the Central American bushmaster,[4] is a species of pit viper in the family Viperidae.

[3][6] Campbell and Lamar (2004) also recognized Lachesis acrochorda (García, 1896) as a valid species,[5] which McDiarmid et al. (1999) had treated as a synonym of L.

Ditmars (1910) reported a specimen from Costa Rica that was 11 feet 4 inches (349 cm).

Solórzano (2004) cites historical records that put the maximum length at 360 cm (11 feet 9¾ inches).

Typically, the species has a pronounced middorsal ridge that is most distinct on the last quarter of the body.