In human pathology, Lewy body diseases (LBD) include idiopathic and familial Parkinson’s disease, pure diffuse LBD, and combined brainstem and neocortical Lewy bodies with Alzheimer’s disease. Three hand-reared Yellow-crowned Amazon (Amazona ochrocephala), from a related pair, had uncoordinated movements, principally head tilt and stargazing. They were unable to perch and eat. Due to the poor condition, the birds were euthanized. Parrots tested negative to ABV and anti-ganglioside antibodies serology. MRI did not get relevant information. At histology, organs had no alterations but brain showed neuronal loss, microspongiosis, reactive astrogliosis with abundant classical Lewy bodies, Pale bodies and axonal spheroids. Some scattered amyloid non-neuritic plaques were observed in the frontal neocortex. Ubiquitin and a-synuclein IHC indicated the presence of Lewy bodies in the above-mentioned structures. Western blot confirmed the presence of a-synuclein uniquely in brains of the sick parrots. In these birds, we measured an impaired functionality of the proteasome, a proteolytic complex implicated in familial parkinsonism.