Controversy exists regarding the timing of surgery for spontaneous pneumothorax (SP), which can be performed either after the first development of pneumothorax or after a recurrent spontaneous pneumothorax has occurred. Treatment after recurrence is often adopted because of the purported low recurrence of SP treated nonoperatively and the historical morbidity of open surgery. However, the effectiveness of VATS (to videoassisted bullectomy and pleurodesis) has raised the possibility of performing primary VATS (PV) in all patients. The authors therefore hypothesized that PV is safe and effective for SP and sought to perform a cost-benefit analysis of PV vs secondary VATS (SV). After institutional review board approval, consecu tive patients with SP (1991-2003) and no comorbidities were retrospectively divided into PV vs SV. Demographics, recurrent pneumothorax after VATS, length of stay, and costs were compared by Student’s t test/χ2. The predicted incremental cost of PV was (cost of PV) -{[cost of nonoperative treatment ×(1 -recurrence rate)] +cost of SV ×recurrence rate}. Data are means ±SEM. There were 54 spontaneous pneumothoraces in 43 patients (11 bilateral), of whom 3 were excluded because of open thoracotomy. Of 51 pneumothoraces, nonoperative treatment was attempted in 37, of whom 20 recurred and thus required SV. Primary VATS was performed in 14. Both groups had similar age, sex, weight, height, admission heart rate, and room air oxygen saturation. Total treatment length of stay was significantly shorter for PV vs SV (7.1 ±0.96 vs 10.5 ±1.2, P =.04). However, morbidity from recurrent pneumothorax after VATS occurredmore frequently after PV than SV (4/14 vs 0/20 P <.05). Based on the observed recurrence rate of 54%, performing PV on all patients with SP would increase cost by ＄4010 per patient and require a recurrence rate of 72%or more to financially justify this approach. Contrary to the hypothesis, the increased morbidity and cost do not justify a strategy of PV blebectomy/pleurodesis in children with SP. Instead, secondary treatment is recommended. Controversy exists regarding the timing of surgery for spontaneous pneumothorax (SP), which can be performed either after the first development of pneumothorax or after a recurrent spontaneous pneumothorax has occurred. Treatment after recurrence is frequently adopted because of the purported low recurrence of SP treated nonoperatively and the historical morbidity of open surgery. However, the effectiveness of VATS (to videoassisted bullectomy and pleurodesis) has raised the possibility of performing primary VATS (PV) in all patients. The authors therefore hypothesized that PV is safe and effective for SP and sought to perform a cost-benefit analysis of PV vs secondary VATS (SV). [Institutional review of institutionalized board approval, consecu tive patients with SP (1991-2003) and no comorbidities were retrospectively divided into PV vs SV. Demographics, recurrent pneumothorax after VATS, length of stay, and costs were compared by Student’s t test / χ2. The predicted incremental cost of PV was (cost of PV) - {[cost of nonoperative treatment × (1 -recurrence rate)] + cost of SV × recurrence rate}. Data are means ± SEM. There were 54 spontaneous pneumothoraces in 43 patients (11 bilateral), of whom 3 were excluded Of of the open thoracotomy. Of 51 pneumothoraces, nonoperative treatment was attempted in 37, of whom 20 recurred and thus required SV. Primary VATS was performed in 14. Both groups had similar age, sex, weight, height, admission heart rate, and room Total treatment length of stay was significantly shorter for PV vs SV (7.1 ± 0.96 vs 10.5 ± 1.2, P = .04). However, morbidity from recurrent pneumothorax after VATs occurred more frequently after PV than SV (4/14 vs 0/20 P <.05). Based on the observed recurrence rate of 54%, performing PV on all patients with SP would increase cost by $ 4010 per patient and require a recurrence rate of 72% or more to financially justify this approach. Contrary to the hypothesis, the increased morbidity and cost do not justify a strategyof PV blebectomy / pleurodesis in children with SP. Instead, secondary treatment is recommended.