In order to gather information on the culicid fauna of Nova Iguac¸u Municipal Park, Rio de Janeiro, Brazil, adult and immature stages were collected with the Centers for Disease Control and Prevention miniature light traps, and dippers and suction tubes, respectively. In all, 828 adult and 990 immature specimens were collected belonging to 12 genera. Among the species collected were Aedes aegypti, Ae. albopictus, Ae. fluviatilis, Ae. scapularis, Haemagogus leucocelaenus, and Psorophora ferox that are considered of potential medical importance. Culicids used a variety of larval habitats and bred under diverse ecological conditions, mostly in natural water containers formed by bamboo, bromeliad, ground depression, rock pool, stream, tree hole, and in artificial containers such as abandoned bathtub, car carcass, abandoned sink, plastic cup, waste tire, and water tank. Species richness and diversity increased from lower to higher forest cover and was highest in sites with highest diversity and high number of larval habitats.