Sibling species A of Anopheles subpictus (fresh water form) has been incriminated and established as a primary vector of malaria for the first time in an area (Tarakeswar, West Bengal) in Indian subcontinent with a natural sporozoite (Plasmodium vivax) rate of 0.32% (2/621). Moderate anthropophilic index (41.0) and high survival rate per gonotrophic cycle (0.58) indicate its efficiency as vector. Coincidence of higher malaria cases and higher density of An. subpictus in the study area is of high relevance. No natural sporozoite infection was detected in other anophelines available like An. vagus, An. annularis and An. barbirostris.