A new CPAP device is described which is simple, lightweight, easily constructed, and not functionally dependent on gravity or valves. The device consists of a conventional T-piece into which a small nozzle is placed opposite, but projecting towards, the patient connection. When a flow of oxygen is delivered through the nozzle, continuous positive pressure within the airway results. The device was evaluated with a mechanical lung model, in human volunteers using various breathing patterns and in intubated patients requiring transport within the hospital. In all three situations, the device provided 7–15 torr endexpiratory pressure and an FIO2of 0.40–0.90 using oxygen flow rates of 10–30 L/min. The device is safe, reliable, and can be easily adapted to provide IMV when required. Clinical applications are discussed.