An adult female crested porcupine (Hystrix cristata) was evaluated for an acute onset of head tilt, circling, and ataxia. She was found dead in animal holding 2 days after exhibiting clinical signs of a neurologic disorder. Histopathology of brain tissue revealed protozoal cysts indicating that a protozoal encephalitis was the cause of death. Immunohistochemical staining of brain tissue for Toxoplasma gondii was strongly positive. The adult male in the same enclosure has demonstrated similar clinical signs for the past 3 years. Toxoplasma gondii has not been reported in this species to date.