Field studies of Dajabon Province, Dominican Republic, revealed that Anopheles albimanus and An. vestitipennis were the most abundant anopheline species followed by An. crucians and An. grabhamii. Three of the species were collected as adults and larvae whereas An. grabhamii was found only in the adult stage. Perennial ponds and rice fields were the most important larval habitats. The anophelines were predominantly exophilic and exophagic; however, outdoor resting sites could not be identified. Large numbers of mosquitoes were collected from corrals at night and also by using an animal-baited net trap and UV light traps. Man-biting collections showed an early evening peak of biting activity by An. albimanus and An. vestitipennis. Only 23% and 13% of the bites by the 2 species, respectively, occurred indoors.