Soil samples were taken during dry and wet months from natural breeding habitats of phlebotomine sandflies in Marigat, Kenya. Soils were analyzed to determine chemical and physical factors; results were related to relative abundance of adult sand flies exiting from the same habitats. Soil pH, organic carbon, exchangeable cations, moisture content, sand, and silt showed differences between habitats during either the wet or dry season or both. Magnesium and clay did not differ between habitats. In burrows, no correlation was observed between sand flies of the generaPhlebotomusRondani&Berté andSergentomyiaFranca&Parrot and soil chemical and physical factors, whereas in termite mounds,Sergentomyiaspecies were negatively correlated with pH and phosphorus. In tree bases, contrasting highly negative and positive coefficients were observed between calcium, manganese, moisture, clay, andPhlebotomusspecies.Sergentomyiaspecies were positively correlated with organic carbon, potassium, and sand during the wet season; they were negatively correlated with pH and positively correlated with magnesium during the dry season. It is concluded that the abundance of sand flies depends to some extent on chemical and physical factors of their breeding places in the soil.