The function of the mini-drain was satisfactory in the majority of cases, but cases with pleural fluid should be avoided. The recurrences were more due to the severe nature of the pulmonary leak rather than to inadequacy of the drain. The side effects mostly occurred in the first patients, so there was a learning curve. The new system should be tried in all patients presenting with an uncomplicated pneumo-thorax allowing ambulatory treatment. Patients with other diseases complicated by pneumothorax could have the new system in order not to be confined to bed. The new system has no place in patients bedridden due to other severe diseases.