Objectives    To investigate the etiological factors

clinical features and treatment of pediatric primary spontaneous pneumothorax (PSP).     Methods    The clinical data of 84 PSP patients under the age of 18 from Departments of Emergency

Respiratory Diseases and Thoracic Surgery of our hospital from June 1999 to June 2009 were collected. There were 72 males (85.7%) and 12 females (15.3%) with a ratio of 6 to 1. Their age ranged from 14 to 18 (mean 17.06). Patients with pneumothorax following trauma

pneumonia

iatrogenic and other underlying causes were excluded. Therapeutic methods included oxygen therapy for 4.8% patients

closed drainage of pleural cavity for 57.1% patients

and surgery for 38.1% patients

But there were 31 patients receiving surgical treatment after closed drainage was failed. The period of follow-up ranged from 1 to 123 months (mean 25.73 months) through telephone or outpatient.     Results    Eighty-four patients were included

of whom 96.4% had chest pain

7.1% had chest tightness

66.7% had dyspnea

8.3% had shortness of breath and 14.3% had cough. There were 96.4% patients having decreased breathing sound and 3.6% having absent breathing sound. Bullae or blebs occurred mostly in apex and upper lobe. Twenty-one patients suffered from recurrent pneumothorax. Smokers (66.7%

n=9) had higher recurrent rate than nonsmokers (22.0%

n=75).     Conclusion    PSP should be considered when symptoms such as chest pain and dyspnea appear in teenagers. Closed drainage of pleural cavity combined with surgical procedure is recommended for treatment. PSP patient with a history of smoking has higher recurrent rate of PSP.