In this paper we present information on fluorescent frogs that will be of use to interested researchers. We describe practical details and provide new data on the phenomenon in Boana punctata, while reporting for the first time its occurrence in the closely related B. atlantica. Both species leave persistent fluorescent marks on the substrate in field and lab conditions, the biological role of which, if any, remains unknown. We discuss briefly the heuristic criteria employed to identify other anuran species most likely to be fluorescent—at least in a similar way to that described in B. atlantica and B. punctata—and provide a list of 281 species in seven families (Arthroleptidae, Centrolenidae, Hemiphractidae, Hylidae, Hyperoliidae, Mantellidae, and Rhacophoridae) that should be tested for the occurrence of fluorescence. Finally, we discuss some general aspects related to anuran coloration, fluorescence, and criteria to assess its biological role, if any, commenting on the role of pteridins and h...