Toxoplasmosis was diagnosed in a vinaceous Amazon parrot based on histopathology and immunohistochemistry. The bird was prostrate on the bottom of the cage and died. Necropsy revealed edema and congestion of the lungs, cloudy air sacs, and mild hepatomegaly. Histopathology revealed severe pulmonary congestion and edema and interstitial mononuclear cell inflammation associated with many cysts containing bradyzoites of Toxoplasma gondii scattered throughout. The heart had mild multifocal lymphocytic myocarditis and free tachyzoites in the muscle fibers, and the kidneys had mild interstitial nephritis and a few cysts containing bradyzoites of T. gondii. Immunohistochemistry was negative for Sarcocystis falcatula and Neospora caninum and confirmed the protozoa as T. gondii. This is the first description of T. gondii in an endangered species of a Brazilian psittacine.