Toxoplasmosis is a frequently diagnosed and often fatal disease of squirrel monkeys (Saimiri sciureus) and other New World primates, but only a single case report of a capuchin monkey (Cebus capucinus) exists in the literature. A 32-yr-old, female, spayed, white-throated capuchin monkey presented to the University of Florida Veterinary Medical Teaching Hospital (VMTH) for paraparesis. The animal was immobilized for a physical examination, which revealed crepitus in the right stifle. The remainder of the diagnostic evaluation, including electromyography (EMG), radiography, complete blood count, and biochemistry panel, was unremarkable. A diagnosis of degenerative joint disease was made and treatment with anti-inflammatory medication was initiated. Despite treatment, the animal worsened and presented to the VMTH 4 days later with tetraparesis. Additional diagnostic testing was pursued, including analysis of cerebrospinal fluid collected from the lumbosacral space. A lymphocytic pleocytosis (20 WBC/μl; 4% neutrophils, 77% lymphocytes, 4% mononuclear phagocytes, and 15% eosinophils) and elevated protein (118 mg/dl) was found, indicative of meningitis due to a protozoal, fungal, or viral etiology. A presumptive diagnosis of protozoal meningitis was made pending titers to Toxoplasma gondii and Neospora caninum. Treatment with clindamycin and trimethoprim-sulfamethoxazole resulted in rapid improvement and complete resolution of clinical signs within 2 wk. Serologic results revealed a negative titer to N. caninum, and a high positive titer to T. gondii (1:131,072). Toxoplasmosis should be considered in the differential diagnosis of capuchins with neurologic signs. Capuchins’ relative resistance to toxoplasmosis may be related to their less strictly arboreal habits, and occasional exposure to felid feces in their natural habitat.