We present the results of a taxonomic review of the four species of Allobates endemic to the Atlantic Forest Domain in Brazil. A total of 880 preserved specimens from 29 localities covering their range in Atlantic Forest were studied based on external attributes. Characters formerly described as diagnostic in original descriptions and others cited for dendrobatids in the literature were studied along the total geographic range of the populations of these species, including the type localities. We found no discrete characters, qualitative or quantitative, capable of differentiating the species. Most local and geographic variation was limited to snout-vent length and color pattern. Considering the lack of evidence otherwise, we use the results of our morphological analysis to allocate all Atlantic Forest species of Allobates to synonymy with Allobates olfersioides.