We present data on the altitudinal distribution of amphibians on the western slopes of Uluguru South Mountains, Tanzania. These mountains form part of the Eastern Arc Mountains, which are known for their biodiversity richness. We used drift fences with pitfall buckets, plots, and audio-visual survey methods. A total of 21 species was found during the survey. Four species previously reported in the Uluguru South Mountains were not found during the present survey. Generally, the number of species was highest at lower altitudes and decreased with increased altitude. Species similarity index showed that the study sites adjacent to each other had greater similarity in amphibian species composition than did sites distant from each other. The Uluguru Mountains are characterized by altitudinal variation in vegetation types and climatic factors such as temperature and rainfall, which may affect the distribution of amphibians on the mountain.