This retrospective study of 2,507 cases of spontaneous pneumothorax (SP) involves 1,873 patients treated at our hospital over nearly 20 years. Men represented 92.4% and most patients were between 16 and 30 years old (56.2%). Presenting more than one episode were 29.7%. The treatment of choice was placement of a pleural drain whenever SP had led to lung collapse amounting to more than 10% of volume. Thoracotomy was performed when the patient had experienced three or more episodes of SP; when a pleural drain had not resolved the condition 10 days after placement; in hemo-SP with severe hemorrhage; and in 2 cases in which SP was bilateral. A total of 419 thoracotomies were performed on 384 patients (20.7%). All episodes were resolved and complications were few. Six patients died (0.32%), three following thoracotomy. All of these had antecedents of chronic obstructive lung disease and all were over 70, excepting one who was 56.