Encephalitis is the most frequent neurologic manifestation of cat-scratch disease although myelitis and radiculitis may occur. Recovery is usually if not always complete. The causative agent of cat-scratch disease remains unknown although viruses of the psittacosis-ornithosis-lymphogranuloma venereum-trachoma group and herpes simplex are implicated. The pathogenesis of the neurologic manifestations is obscure. (25:23-27, 1971)