A persistent pulmonary air leak, whether as a result of pulmonary surgery or as a result of a traumatic or spontaneous pneumothorax, is a difficult and frustrating problem to manage. Several therapies have been employed, including thoracotomy and repair of the air leak, prolonged tube thoracostomy suction, and chemical pleurodesis. We report two cases in which patients with a prolonged air leak who were not candidates for thoracotomy had immediate successful treatment with an autologous "blood patch" pleurodesis. An autologous blood patch pleurodesis is, in our limited experience, a simple, painless, inexpensive, and effective treatment for patients with a persistent pulmonary air leak.