We report the successful treatment of lipoid proteinosis in a 41-year-old man using oral dimethyl sulphoxide. The initial dosage was 40 mg/kg/day, which was then increased progressively to 60 mg/kg/day. After 3 years of treatment, the patient's skin lesions, hoarseness of voice and abnormal oesophageal function improved remarkably. No side-effects were noted except for a garlic-like smell on the patient's breath.