The current study is designed to compare the effectiveness of brushing the pleura vs. instillation of minocycline for the management of primary spontaneous pneumothorax, and to assess the sensitivity of echography in defining areas of defects. Blebectomy and pleurodesis were carried out thoracoscopically on 84 patients. In group A (42 patients), abrasions were induced using a sponge on a long ring forceps. Group B (42 patients) received intrapleural instillation of minocycline. Echography was carried out two weeks after discharge and then repeated two weeks later. Follow-up ranged between 28 and 39 months. Two patients were excluded from group A for incomplete follow-up. In group A, five patients (12%) showed areas of free mobility of the lung on first echography. At the second examination, three (7% of the total) showed the same areas of mobility; one patient developed an attack of localized pneumothorax after 32 and another after 45 weeks. Each had three adjacent areas of free mobility. In group B, two patients each showed one area of free mobility on the first and second examinations but no recurrence during follow-up. The two groups had comparable chest drainage, postoperative hospital stay and complication rates. The patients in group B demonstrated a trend towards a decreased rate of prolonged air leaks (2% vs. 5%; P=0.100). Thus, pleurodesis by instillation of minocycline as a part of thoracoscopy is more effective than brushing the pleura. Thoracic echography is a highly sensitive method for assessing the effectiveness of pleurodesis.