There is a very small number of patients who suffer from acne even in the sixth and seventh decades of life. These patients have suffered from acne for most of their lives, 30–60 years, and have often received multiple courses of antibiotics over many years. We saw 10 such patients over 4 years. One received oral isotretinoin 1 mg/kg per day, but was unable to tolerate the adverse effects of cheilitis and developed hyperlipidaemia. We subsequently treated nine others with oral isotretinoin, 0.25 mg/kg per day, for 6 months; in six the acne had virtually cleared by 3–4 months while the other three cleared by 6 months. Up to 36 months after therapy these patients have remained clear of acne except for one who relapsed after 11 months. Therefore, as these patients respond well with few side-effects both in the long- and short-term to low-dose isotretinoin, they should be treated with isotretinoin, although at the lower starting dose of 0.25 mg/kg per day compared with younger patients who are treated with 0.5–1 mg/kg per day, and the treatment maintained for 6 months.