Abstract:Objective:To study the cause of erroneous diagnosis and in-effects on the spontaneous pneumothorax in elderly patients.Method:The clinical data were analysed on 46 elderly patients and 56 young or middle aged patients with the spontaneous pneumothorax.Result:Most elderly patients with the spontaneous pneumothorax had underlying lung disease with typical dysprea, most types were open or tention pneumothorax. Lung expension time was longer、 an these were significantly difference to the control group(P<0.01).Conclusion:The elderly spontaneous pneumothorax was an emergent situation with atypical symptom or erroneous diagnosis. The prompt diagnosis and treatment might decrease the mortality and the erroneous diagnostic rate.