A longitudinal study on malaria transmission was conducted from January 1983 to December 1988 in two villages of Dimapur PHC in Nagaland. A diverse anopheline fauna comprising of 23 species was identified including three species viz. An. aitkeni, An. bengalensis and An. insulaeflorum which were observed in larval stages only. An. vagus was the predominant species followed by An. philippinensis, An. culicifacies and An. minimus. An. minimus though maintained relatively high density throughout the year manifested two peaks in June and October. An. fluviatilis and An. dirus though found in relatively low density their seasonal prevalence was suggestive of a post-monsoon and monsoon species respectively.