A symptomatic pneumothorax, whether large or small, and a pneumothorax in any patient with underlying pulmonary disease or previously diagnosed poor pulmonary reserve, can be afforded immediate treatment by a simple technique of insertion of a newly designed pneumothorax catheter. Particularly in the cases of pneumothorax complicating needle aspiration biopsies, the catheter is recommended for immediate treatment in order to prevent any possible serious complications. The method is extremely simple and safe, and has been used successfully in more than 20 cases. The catheter insertion does not require any advanced surgical skill or training. The use of this procedure is suggested as a reliable expedient for immediate treatment of any pneumothorax that may present as an emergency in the Radiology Department.