Cat-scratch disease is usually mild, often unrecognized and almost certainly caused by a microscopic agent. All of 152 patients with this disease had significant lymphadenopathy, but only 8.5% of these progressed to suppuration. An inoculation site was found in 96.2% of the patients, usually on the upper extremities or head. These percentages vary greatly from those in previous reports. All except two patients had a history of cat contact. Complications in this series include thrombocytopenic purpura, encephalitis, an osteolytic lesion and Paranaud's syndrome (oculoglandular fever). Treatment of the disease should be mainly symptomatic. Aspiration is the treatment of choice for suppurating nodes. Antibiotics are probably valueless in either the prevention or treatment of this disease and its complications.