We provide the first evidence of the presence of the Persian Gulf Sea Snake, Hydrophis lapemoides (Gray, 1849), along the coast of Bangladesh. This species was assumed to exist in there, but neither specimens nor confirmed observations exist until now. We document here the first confirmed record of H. lapemoides based on a freshly collected and taxonomically verified specimen from coastal Bangladesh. The Bangladeshi specimen had the following diagnostic characters: 55 black bands, a dorsal scale composition of 35:51:43, 342 ventrals, one pre-ocular, two post-oculars, 2+3 temporals, 8 supralabials (II largest and contact prefrontals; III–IV contact orbit) and 8 infralabials (I–IV contact genials).