Necropsy of a South American red squirrel (Sciurus granatensis), with clinical signs of neurological disease, disclosed multifocal parasitic granulomata in the brain, lung and myocardium. Lesions were noted in the cerebral hemispheres and subcerebellar white matter. The parasite was identified as a larval ascarid. History of close contact with excreta from raccoons suggested the larvae were that of Ascaris columnaris, an intestinal nematode of the raccoon.