BACKGROUND We investigated the role of observation or insertion of a small French pigtail catheter with Heimlich valve as alternative management to a tube thoracostomy for iatrogenic pneumothorax complicating central venous catheter (CVC) insertion. METHODS A retrospective review of 9,637 consecutive patients who had had subclavian CVCs inserted on an outpatient basis identified 100 patients with pneumothoraces. Treatment consisted of (1) observation, (2) outpatient insertion of a Heimlich valve, or (3) inpatient tube thoracostomy. RESULTS The median pneumothorax size was 10% (range 1% to 100%). Fifty-eight patients had observation as initial treatment, and this strategy was successful in 35 (60%). Thirty-four patients were treated initially with Heimlich valves, and this strategy was successful in 29 (85%). Tube thoracostomy as initial therapy was successful in 7 (88%) of 8 patients. Patients in who initial treatment failed were treated with insertion of a Heimlich valve or tube thoracostomy. CONCLUSIONS In appropriately selected patients, pneumothorax after insertion of a subclavian CVC can be successfully managed in the outpatient setting with observation. Patients in whom observation fails can be treated with insertion of a Heimlich valve. Tube thoracostomy can be reserved for refractory PTX or emergent situations.