Pneumomediastium in a newborn baby is a rare condition and is usually manifested by respiratory and circulatory distress syndrome. We recently have experienced a newborn baby of severe tension pneumomediastinum associated with bilateral pneumothorax. The patient in this report was a day old female and the mother of the baby a lot of difficulties during her delivery and the aid of vaccuum was necessary. This patient was received closed thoracotomy and followed by explothoracotomy and excision of tension multiple air bubbles. The post-op. course is not uneventful.