BackgroundThe delimitation of cryptic species is a challenge for biodiversity conservation. Anurans show high cryptic diversity levels, and molecular species delimitation methods could help identify putative new species. Additionally, species delimitation approaches can provide important results for cryptic species conservation, with integrative methods adding robustness to results.Ischnocnema manezinhowas described from Santa Catarina Island (SCI), southern Brazil. More recently, some inventories indicated continental populations supposedly similar in morphology to it. If these records are confirmed asI. manezinho,it would likely change its endangered status on National Red List, removing the species from conservation agendas. We investigated the threatened frogIschnocnema manezinho, to evaluate if the continental populations belong to this species or if they form an undescribed species complex.MethodsWe used coalescent, distance, and allele-sharing-based species delimitation methods and integrative analyses of morphometric and bioacoustics traits to test evolutionary independence betweenI. manezinhofrom SCI, Arvoredo Island, and continental populations.ResultsIschnocnema manezinhois restricted to Santa Catarina Island, while the five remaining lineages should be further investigated through a taxonomic review. Our results point to a small geographic range ofIschnocnema manezinho. Additionally, the species occurs in isolated fragments of forest in SCI surrounded by expanding urban areas, confirming its status as Endangered. Thus, the protection and monitoring ofI. manezinhoand the taxonomic description of the continental and Arvoredo Island candidate species should be priorities.