Snake gourd is one of the edible crop plant of the genus Trichosanthes which is reported to be the largest genus of Cucurbitaceae family and containing about 90–100 species. The place of biological diversity for this crop existed in southern and eastern Asia right from India to Taiwan and also extended up to the Philippines, Japan, and Australia, Fiji, and even in the Pacific Islands. Snake gourd is extensively grown in tropical parts of the globe, mostly because of its culinary use of the immature fruit. This crop is regarded as a reported source of various macro- and micro-elements and dietary fiber. In spite of their commercial and nutritive significance, very little effort has been devoted for its systemic genetic improvement during the past decades. Nevertheless, in recent times many public institutions in India started systemic breeding program of snake gourd. In this chapter the genetic resources of snake gourd and the research works devoted toward its use in genetic improvement have been meticulously reviewed and documented.