We undertook a 15-day survey of the amphibian fauna of the Mitaraka massif in southwestern French Guiana during the rainy season. We detected 56 species (12 species detected for the first time), including six only thanks to their calls. Thirteen additional species were previously detected from nearby sites. The total number of species occurring in the area is at least 69 but most of the species associated with temporary ponds remained undetected. Therefore, we assume the amphibian community of the Mitaraka massif could reach at least 75 species, which represents one of the richest amphibian faunas of the Guiana Shield. With at least six species not occurring further north in French Guiana, the amphibian fauna of the Mitaraka massif is notably distinct from the rest of the territory. Seven of the species discovered during the survey are highlighted here either because these new records represent range extensions or because they are putative new species.