Stromanthe bahiensis Yoshida-Arns, Mayo & J. M. A. Braga sp. nov. (Marantaceae) is described as an endemic to the Atlantic Forest coast of southern Bahia State in Brazil. It is similar to S. hjalmarssonii (Körn.) Petersen, which is restricted to Central America, but differs from it by the following characteristics: petiole 14–70 cm long, leaf blade oblong-ovate to ovate-lanceolate, fertile bracts 18–30×2–4 mm, narrowly lanceolate to ovate-lanceolate, sepals 4–6 mm long, corolla lobes 3.0–3.5 mm long, outer staminodes 2.0–3.5×1–2 mm, pale bluish or purplish, callose staminode 2–3×1–2 mm, cucullate staminode 2–3 mm long and ovary hirsute. The new species is described and illustrated with diagnostic characters, taxonomic comments and remarks on its conservation status.