Eighteen neonates 33 to 42 wk gestational age with severe respiratory failure were referred for extracorporeal membrane oxygenation (ECMO). Sixteen ultimately met the ECMO criteria, of whom 15 were first offered high-frequency oscillatory ventilation (HFOV). Seven responded to HFOV alone and did not require ECMO treatment. Eight of the nine remaining patients were placed on ECMO support with HOFV. Infants who responded to HFOV alone tended to have pneumonia more than meconium aspiration, to be smaller and more immature, to have higher Apgar scores, and to have suffered severe hypoxia (alveolar-arterial oxygen pressure difference over 600 torr) for less time than the ECMO group. Although patient numbers are small, a trend is noted which favors HFOV treatment alone in terms of the duration of HFOV, the total duration of assisted ventilation, the rapidity with which extubation was accomplished, and the length of hospital stay.