This study is an evaluation of the smoking behaviour of patients treated with ear acupuncture for smoking cessation. A total of 249 patients who had undergone ear acupuncture for smoking cessation between 1985 and 1998 in a practice in Switzerland were asked before the first treatment to fill in a form regarding their smoking behaviour and retrospectively in autumn 1998 a questionnaire regarding the success of therapy. Ear acupuncture treatment consisted of two consultations at an interval of 10 days. The response rate was 53.8%. The Kaplan Meier analysis of the abstinence time yielded a 1-year success rate of 41.1%. Men gave up smoking more easily than women. Start of smoking as well as start of treatment between the age of 20 and 40 years were favourable conditions for smoking cessation. People who had smoked 20 cigarettes or more per day before treatment profited most. People who smoked as a way of passing the time or because of tediousness found it easier to stop smoking than people who smoked because of nervousness.