A new species of tree frog from the Scinax catharinae species group is described, discovered in the Municipality of Ouro Preto, southeastern Brazil. The new species is related to Scinax flavoguttatus, but differs from this species mainly by the light green color on its inguinal regions and hidden portions of flanks and thighs, by its subovoid snout, by its developed nuptial pad, and by its smaller males and females. Additionally, we describe the tadpole which is characterized by: dorsal position of nostril; dorsolateral eyes; gold spots between nostrils and eyes, short spiracle; spiracle opening on the midline of dorsal and ventral surface of body; absence of tail flagellum; oral disc with a short dorsal gap, surrounded by a uniseriate marginal papillae; M- shaped upper jaw sheath; tooth row formula 2(2)/3.