Avian bornaviruses are the causative agents of proventricular dilatation disease (PDD), a fatal neurological disease considered to be a major threat to psittacine bird populations. We performed a survey of the presence of avian bornaviruses and PDD in pet psittacines in Brazil and also studied PDD's clinical presentation as well as the genomic variability of the viruses. Samples from 112 psittacines with clinical signs compatible with PDD were collected and tested for the presence of bornaviruses. We found 32 birds (28.6%) positive for bornaviruses using reverse transcriptase polymerase chain reaction (RT-PCR). Twenty-one (65.6%) of the 32 bornavirus-positive birds presented neurological signs, seven (21.9%) presented undigested seeds in feces, four (12.5%) showed proventricular dilatation, six (18.8%) regurgitation, three (9.4%) feather plucking and three (9.4%) sudden death. The results confirm that avian bornaviruses are present in pet psittacines in Brazil, and sequence analysis identified a distinct virus, named parrot bornavirus 8 (PaBV-8).