In this first paper of a series on mosquitoes of the mangrove forests of India, details of mosquito species recorded in Bhitarkanika, Orissa, are presented. Forty-three species of mosquitoes belonging to 21 subgenera and 13 genera, Aedes, Anopheles, Armigeres, Coquillettidia, Culex, Ficalbia, Heizmannia, Lutzia, Mansonia, Ochlerotatus, Toxorhynchites, Uranotaenia, and Verrallina, were recorded. Predominant larval habitat was the tree holes, from which 15 species were taken. Adults were mostly found resting in crab holes, tree holes, and hoof prints in the forest area and on walls in the guesthouse area. About 14 species were caught in light traps, while 19 species landed on humans for feeding. Ae. franciscoi and Oc. feegradei are 2 new country records for India. Ae. cancricomes and Cx. perplexus, known only from Andaman Islands of India, are new records for mainland India.