Krefft's warty frog is endemic to both lowland and upland regions of southern Kenya and northern and eastern Tanzania. In Kenya it is restricted to the Taita Hills and Shimba Hills while in Tanzania it is found in the Pare Mountains, the Usambara Mountains, the Uluguru Mountains, the Nguru Mountains, the Ukaguru Mountains and the Udzungwa Mountains. It occurs at heights ranging from above sea level. It lives among leaf litter in forests, hiding under rocks and fallen logs or scrambling about in low vegetation, but can also be found in cleared areas near the edge of forests. It is sometimes found in the leaf axils of banana plants.