The treatment of spontaneous pneumothorax in the civilian population can be influenced by the age of the patient and the presence of associated pulmonary disease. The medical records of 130 patients who presented with 168 occurrences of SP were reviewed during an 11-year period (1973 to 1984). Follow-up was from a minimum of 30 months to 13 years (mean 6.3 years). The therapeutic options included observation alone (40 occurrences), thoracentesis (6 occurrences), chest tube thoracostomy (102 occurrences), and thoracotomy (20 occurrences). Treatment of SP should be prompt with the objective of complete re-expansion of the lung and prevention of recurrent pneumothorax. This should be accomplished by the use of chest tube thoracostomy with early addition of thoracotomy as necessary. Selected use of thoracentesis can be effective. The use of observation alone can be dangerous and is associated with a higher recurrence rate.