Abstract: A herpetological survey was carried out to study the diversity of snakes from 2002 to 2004. The study revealed eighteen species of terrestrial snakes belonging to five families. Out of which four species were highly venomous species; two were mildly venomous and the rest of the twelve were non poisonous species. Two species were endemic to Sri Lanka and six out of the eighteen documented species were recorded for the first time from Jaffna Peninsula.