Between 1983 and 1987, 114 adult patients with 131 pneumothoraces were treated utilizing catheter aspiration for simple pneumothorax as an alternative to tube thoracostomy. The causes of simple pneumothorax were as follows: 79 needle-induced, 36 spontaneous, and 16 traumatic. Thirty-eight of the pneumothoraces were small (less than 20% of volume), 55 were moderate (20% to 40% of volume), 36 were large (greater than 40% of volume), and 2 were of unknown size. Overall, catheter aspiration for simple pneumothorax was successful in 90 patients (69%). The success rate was 75% with needle-induced, 53% with spontaneous, and 75% with traumatic pneumothoraces. Small pneumothoraces were successfully managed with catheter aspiration for simple pneumothorax in 87% of patients, moderate-sized in 60%, and large in 61%. There were three complications (2.3%), including one hemothorax and two retained sheared catheter tips. The average cost per patient was +868 for catheter aspiration, and $6402 for a tube thoracostomy. These data support catheter aspiration as a safe, cost-effective, and successful technique for managing simple pneumothorax.