The order Squamata is divided into 12 families, on the basis of their habit and habitat and various characteristics. Some of the families are divided into subfamilies.

In Pakistan, 8 families and 64 species of snakes are found which are widely distributed throughout the country. 50 species are terrestrial and 14 are marine. Out of 50 terrestrial species, 10 are poisonous and 40 are non-poisonous. All 14 species of sea snakes are venomous. This section gives a brief description of the families with the important snakes found in Pakistan.