A pilot study with the anti-leprosy agent clofazimine was conducted on seven patients with cheilitis granulomatosa or complete Melkersson-Rosenthal syndrome. Beneficial effects were observed in all patients, dependent on the degree of the clinical expression of the disease: the variable attacks of lip swelling, characteristic for the edematous phase of this disease, were suppressed promptly and completely in all patients. Persistent residual swelling of the lips, caused by cellular inflammatory infiltrates, which was present in four patients prior to therapy, responded much less rapidly and--in three out of four--only incompletely. After drug withdrawal, four patients remained free of symptoms for periods ranging from 5 to 45 months; the remaining three patients relapsed after intervals of 3-18 months. The mode of action clofazimine takes in cheilitis granulomatosa is not understood at the present time but is likely to be linked to the phagocytosis-stimulating effect of this drug on macrophages.