1. The reported 22 cases of unilobar obstructive emphysema in infancy are reviewed. Eighteen of these cases were successfully treated by lobectomy or segmental resection. No cause of the obstruction was found in over 50% of the cases reported. 2. Two cases of unilobar obstructive emphysema in the newborn are presented. These patients were successfully treated by selectively decompressing the emphysematous lobe. 3. The non-surgical method of treatment is advocated in the newborn when lobar emphysema is newly established and reversible. It may be of value when surgery is indicated to improve the patient who is a poor risk. 4. The mechanism, by which selective decompression alleviates the partially obstructed bronchus, is open to conjecture. However, we postulate that the bronchus, is kinked by an overdistended emphysematous lobe and that retained viscid secretions augment the bronchial obstruction in the new born.