<p>Snake venom, like most eukaryotic venom, consists of multiple proteins and peptides, each of which belongs to a particular family represented by many different classes and each class may be represented by multiple isoforms. For most of history, venom studies have mainly been focused on the clinical aspects of how to treat the envenomated or to repurpose toxins for pharmaceuticals. However, with the advent of omics technology, venom is no more just a tool to be used for development of therapeutics. Instead, molecular studies with venom have opened a whole new avenue to understand the evolutionary and ecological attributes of an extremely dynamic system across eukaryotes. This review consists of two different parts, the first of which deals with various patterns identified in the molecular evolution of snake venom and the second deals with how various features of ecology and environment has shaped their diversity across various regions. The molecular evolutionary patterns have been limited to the three most dominant venom families, widely represented across all major venomous snake taxa. The final part of the review is focused around how venom proteins and their targeted molecules have co-evolved in certain genera.</p>