We inventoried the bird fauna of an isolated enclave of white-sand vegetation, known locally as a campina/campinarana, in the western extreme of the Brazilian State of Acre between 22 and 31 January 2007 (wet season). A total of 114 bird species was registered in 1,425 net-hrs of mist-netting and 8 hrs of recordings of vocalizations. This included six species known to be associated with campinas and campinaranas in western Amazonia. A number of important records were made of species endemic to the southwestern Amazon Basin, but poorly-known in Brazil. Despite the relatively small size of the campina/campinarana enclave, these records indicate the area is extremely important for conservation of local biodiversity, and reinforces the need for further studies of both the avifauna and other groups of animals.