The impact of acne on quality of life can be profound. Although treatment improves the clinical features of acne, there is little information on its benefit from the patients' point of view. In this study, patients with acne referred to a dermatology clinic were sent questionnaires before being seen, and 4 and 12 months afterwards. Clinical severity was assessed by a dermatologist at baseline and at 4 months. Quality of life was assessed by patients using the Short Form 36 instrument (SF-36), the Dermatology Life Quality Index (DLQI), Rosenberg's measure of self-esteem and the General Health Questionnaire (GHQ-28). Of 90 available patients, 79 (89%) returned at least one follow-up questionnaire. The clinical acne grade improved substantially with treatment. There were also significant improvements either at 4 or 12 months in the DLQI, self-esteem, GHQ-28 and all five dimensions of the SF-36 that were impaired at baseline. Quality of life continued to improve between the 4- and 12-month follow-up questionnaires. Clinical and patient-assessed outcomes were significantly better in patients treated with isotretinoin. The study showed that disability caused by acne can be largely reversed by effective treatment. It also showed that patient-assessed measures of outcome can respond to changes over time and discriminate between treatments differing in effectiveness.