We prospectively assessed the safety and cost saving of a small-bore drain based procedure for outpatient management of first episodes of primary spontaneous pneumothorax. Patients were managed by observation alone or insertion of an 8.5-F "pig-tail" drain connected to a one-way valve, according to size and clinical tolerance of the pneumothorax. All patients were reassessed after 4 h, on the first working day after discharge and on day 7. Patients still exhibiting air leak on day 4 underwent thoracoscopy. The primary end-point was complete lung re-expansion at day 7. 60 consecutive patients entered the study. 48 (80%) met the definition of large pneumothorax. The success rate was 83%. The 1-year recurrence rate was 17%. 36 (60%) patients were discharged after 4 h and 50% had full outpatient management. No severe complication was observed. The mean ± SD length of hospitalisation was 2.3 ± 3.1 days. This policy resulted in about a 40% reduction in hospital stay-related costs. The present study supports the use of a single system combined with a well-defined management algorithm including safe discharge criteria, as an alternative to manual aspiration or chest tube drainage. This approach participates in healthcare cost-savings.