The breeding sites and biology of Phlebotomus pedifer was investigated in the caves of the old focus of cutaneous leishmaniasis in Mt Elgon, Bungoma District, Kenya. Phlebotomus pedifer was found to rest mainly in the poorly lighted areas of the caves, on the roof, the floor of caves under objects, and in cracks and crevices inside the caves. The flies were also found in abundance in cracks and crevices outside the caves where hyraxes were found to rest. Immature stages of P. pedifer were recovered from wet areas of the floor of the caves. The biology of this species was investigated and the mean duration from egg to adult was 37 days.