21 patients had pleural drainage with a rubber valve (Heimlich) on account of pneumothorax (15) and massive pleural effusion (6). The method succeeded in every case. It has the advantage that it dispenses with suction and bottles, that it needs no turning-off when the patient gets up, but maintains its draining action, and that in cases of persisting broncho-pleural fistula there is no additional suction. The technique represents a simplified alternative to the customy methods of pleural drainage.