A detailed study of the Sea snakes (Family: Hydrophiidae) Recurring in the Indian Ocean has revealed the presence of thirty nine species included in twelve genera. In this paper the systematics, ecology and distribution of nineteen species embraced in eight genera, which are present in the collections of the Zoological Survey of India, are given. The distribution pattern of all the valid species known to occur in the Indian Ocean are also included from a detailed study of the literature.