ABSTRACT: A new species of treehunter, Cichlocolaptes mazarbarnetti sp. nov., is described from a specimen that for many years had been confused with Philydor novaesi. The morphology of this specimen, collected in 1986 at Pedra Branca, Murici, Alagoas, at 550 m elevation (currently the Murici Ecological Station), suggests its allocation in the genus Cichlocolaptes. The new species differs from P. novaesi by its considerably larger size, heavier body-mass, darker and more uniform forehead and crown, absence of buffy periocular-feathers, and a pale orange-rufous tail that contrasts with the rump and the rest of the dorsal plumage. It also has a flat-crowned appearance and a larger, deeper-based, and generally stouter bill. Behavioral specialization on bromeliads and vocal repertoire also suggest that the new species belongs in the genus Cichlocolaptes. The song of this species is markedly different from that of P. novaesi, and it closely matches that of Cichlocolaptes leucophrus. The new species is endemic to the ‘Pernambuco Center’ of endemism, where it inhabits dense, humid forests in hilly terrain. It is known from only two localities in northeastern Brazil, one each in the states of Alagoas and Pernambuco. Taken together, these areas contain less than 3,000 ha of suitable habitat for the species, where we estimate the population during our studies to have numbered no more than 10 individuals. We propose that this species should be categorized as Critically Endangered at a national and global level, and we consider the situation of its conservation to be critical in that it will require urgent action to avoid its global extinction.