Spontaneous pneumothorax can be a complication of several pulmonary diseases, such as pulmonary emphysema, chronic bronchitis and interstitial pulmonary disease. Nevertheless, it is a rare complication of any pneumonia, there is no description of necrosis or abscess caused by Pneumocystis Carinii pneumonia. We present a case of spontaneous pneumothorax (which was not resolved), being a reason for admission, of a patient with AIDS who developed Pneumocystis Carinii pneumonia during the stay in hospital. We think that spontaneous pneumothorax can register bad evolution in patients with AIDS and pulmonary symptoms.