Porthidium is a genus of venomous pitvipers found in Mexico and southward to northern South America. The name is derived from the Greek word portheo and the suffix -idus, which mean "destroy" and "having the nature of", apparently a reference to the venom. As of August 2016 nine species are recognized as being valid. The snakes of the genus Hypnale in southern India and Sri Lanka look quite similar to those of this genus, possibly an example of convergent evolution.