The management of prolonged air leakage (PAL) is a significant clinical challenge, particularly for patients who are unfit for surgical treatment. The use of endoscopic interventions with occlusive devices has been reported previously; however, local availability and cost may represent potential hurdles, especially in developing countries. In this study, we presented a conical endobronchial plug of our design and evaluated the efficacy of making use of that in the treatment of PAL as a novel method. This retrospective study included a total of 23 patients with PAL who were not suitable for surgery and underwent bronchial occlusion using customized plugs. The responsible bronchi were identified by the balloon occlusion test or by end-tidal carbon dioxide detection. In each case, the plug was grasped at the knot of the tip with forceps and then inserted into the target bronchus with a flexible bronchoscope. Of the 23 patients with intractable pneumothorax, 1 to 3 plugs (median =1) were successfully inserted into the affected bronchi of each patient for bronchial occlusion. Air leakage showed complete cessation in 13 patients (56.5%) and reduction in seven patients (30.4%). A total of 20 patients (87.0%) experienced successful removal of the drainage tube following plug occlusion or presented with additional pleurodesis. Complications included expectoration of the plug (n=1) and fever (n=1); no other severe complications were observed. Bronchial occlusion using customized endobronchial plugs appears to be an effective and simple option for the management of PAL in patients who are not suitable for surgery, especially in developing countries, as the customized plug is a cost-effective alternative.