A number of natural and man-made habitats in Marigat area of Kenya were surveyed for sandflies in 1985/86. Of the 98,573 adult sandflies collected, 2.7 % belonged to the genus Phlebotomus and 97.3% to Sergentomyia. Relative abundance of sandflies of the genus Phlebotomus was four times higher in burrows than in termite hills, while sandflies of the genus Sergentomyia collected from termite hills were twice as numerous as those from burrows. Termite hills had the highest sandfly population compared to other sites, followed by tree holes and animal burrows. Fifteen species were identified, of which five belonged to Phlebotomus and 10 to Sergentomyia. The most abundant and widespread species were Sergentomyia antennatus, S. bedfordi, S. ingrami, Phlebotomus martini, S. schwetzi, S. africanus and P. duboscqi. Sandflies of both genera were present for the greater part of the year. Most species of sandflies decreased in numbers during the dry season. High population densities of sandflies were recorded during the wet period. Correlations between relative abundance of sandfly vectors of leishmaniases and rainfall were positive. However, none of the correlation coefficients was statistically significant.