We name and describe a new species of Anura, Pristimantis iiap, from the lowlands of the Peruvian Amazon, and allocate it to the Pristimantis conspicillatus group (sensu Padial et al. 2014). The new species was collected along the Sepahua River, a small tributary of the Urubamba River (Departamento Ucayali, Peru) running west from the slopes of the Fitzcarrald Arch. Individuals were found active at night in the understory of evergreen lowland forest with high density of bamboo (Guadua spp.). The new species is characterized by having complete and conspicuous dorsolateral folds, a slightly granular belly, a first finger slightly shorter than second, with large discs on fingers and toes (especially Fingers III and IV), a bright orange groin, and by lacking well-defined orange spots on the back of thighs and shanks. The advertisement call is composed of a single pulsed note with an average of 15 pulses/note, a pulse rate of 205 pulses/s, an average call length of 75 ms, and average fundamental and dominant frequencies of 1857 Hz and 3690 Hz, respectively. Pristimantis iiap occurs in sympatry with three other species of the group, P. buccinator (Rodríguez, 1994), P. fenestratus (Steindachner, 1864), and P. skydmainos (Flores and Rodríguez, 1997). Although only known from two close localities, we expect P. iiap to occur in similar forests along the Fitzcarrald Arch and on the eastern slopes of Cordillera Vilcabamba and Cordillera del Sira.