Frogs assigned to the monotypic genus Madecassophryne (Anura, Microhylidae, Cophylinae), and possibly belonging to Madecassophryne truebae, were found in December 2016 in two low-altitude localities, Ambahavala and Kapilavato, in the Anosy Mountain in southeastern Madagascar. This poorly known genus was described in 1974 based on osteology, and neither verifiably identified photos of living specimens nor molecular information were available until now. We here update the available information on these enigmatic frogs and provide new data on morphology, osteology, bioacoustics and observations on their habitat, together with a preliminary molecular phylogenetic study, suggesting that Madecassophryne is highly divergent from other members of the cophyline clade.