The author's experience has confirmed the circulatory efficacy of closed-chest cardiac massage. However, it cannot be relied upon for pulmonary ventilation. In curarized adults, with the head unsupported, rhythmic sternal pressure produced no respiratory tidal exchange, because of pharyngeal obstruction by the tongue. With the trachea intubated, sternal pressure produced an average tidal volume of 156 ml. in curarized subjects and no tidal exchange in patients with cardiac arrest. Sternal pressure failed to reoxygenate 5 of 6 hypoxic curarized subjects. Therefore, rhythmic sternal pressure must be accompanied by intermittent positive-pressure ventilation; coordinating ventilation and pressure is desirable.