The systematic position of the agamid genus Coryphophylax (Squamata: Agamidae) is given as monotypic and endemic to the Andaman and Nicobar Islands in the Bay of Bengal, India. After having surveyed intensively in thirteen different Islands and examined several individuals in the Andamans group of islands, we describe a second species of Coryphophylax from the lowland rainforests of the South Andaman Island. Coryphophylax brevicaudus sp. nov. is differentiated from its congener, C. subcristatus (Blyth, “1860” 1861) by its smaller size, relatively shorter tail, presence of nuchal and dorsal crests in both sexes, midbody scale row counts and colour pattern. The new species lives in sympatry with C. subcristatus. The taxonomic history and systematic status of the genus Coryphophylax are discussed, and the need for continued surveys in the Islands is emphasized.