A new species of the genus Phasmahyla is described from an Atlantic Rain Forest remnant at Serra do Timbó, Municipality of Amargosa, State of Bahia, Brazil. The new species is recognized by its medium size for the genus (snout-vent length 32.4 to 35.8 mm in males); reduced to absent coloration with purple spots on concealed surfaces of arm, forearm, thigh, tibia, tarsus, and digits; male with moderate nuptial pad of minuscule horny asperities on finger I; tympanum distinct only on ventral half; dorsolateral glands well developed; dorsal skin slightly coarse; larval oral disc with distinct anterior and two posterior series of horny teeth; interrupted first posterior series of horny teeth slightly larger than the anterior one. Temporal and spectral parameters of the advertisement call are described for the new species, and for the first time for the genus Phasmahyla.