Background: Primary and secondary tumors of the abdominal lower third of the bony thorax are relatively rare. Therefore, indications and techniques for chest wall reconstructions in this area are not well defined. Methods: The techniques for reconstructing basal chest wall defects using the diaphragm are described. Indications for phrenoplasty are limited to reconstruction after full-thickness resection of at least two of the last four ribs in the midaxillary line. The diaphragm can be used for reconstructive purposes both if it is intact and if it is partially involved in the resection of the chest wall. Results: At our institution, the abovementioned reconstructive technique was successfully performed in five patients with an uneventful post-operative course. Conclusions: The main advantages of these methods are the use of promptly available, high-quality autologous tissue and the exclusion of the pleural space from the defect area, thus transforming a thoracic defect into an abdominal one. The disadvantage is a variable reduction in the volume of the hemithorax. These techniques could be compared with other reconstruction techniques using pre-/post-operative respiratory functional tests.