In 10 anesthetized and paralyzed rabbits, cardiovascular variabled(blood pressure, pulse rate), rectal temperature and arterial blood gase tension were investigated during high frequency oscillatory ventilation(about 17hz). During high frequency oscillation(HFO) blood pressure, rectal temprerature and blood gas tension remained stable and were not different from the control values( intermittent positive pressure ventilation IPPV). The PaO2/FIO2 ratio remained unchanged during the experiment in spite of changing airway pressure. We observed that HFO provided adequate ventilation and oxygenation without altering cardiovascular dynamics. High frequency oscillatory ventilation appears to be a promising new way of achieving gas exchange with minimal risk of barotrauma to the lung.