Among vertebrates the snakes are most fascinating creature. Most of the snakes are shy and will not attack peoples unless they are harassed. Due to their remarkable features they are assumed beneficial creature so it is a time know more about them. All snakes are classified into fifteen families of which only three are venomous i.e. Elapidace, Viperidae and Cortalidae. Snakes are considered as a victim of large number of parasites representing a wide range of pathogens and parasites that causes infection. Studies carried out of Russell's viper which causes fatal snakes bite in Pakistan. Several species of nematodes has been reported from viper snakes in Pakistan. During the present study nematode parasites were collected from intestine and mounted slides to study the taxonomical details. For histopathological studies tissues of intestine was fixed in 5% buffer formalin. The sections cut at the thickness of 3-5 micron and stained with hematoxylin and eosin. The microscopic observations revealed atrophy of hepatocytes, ulceration, atrophy, granulomas, intense fibrosis, hypertrophy, and other inflammatory responses in intestine.