Surgical stabilization of rib fractures has been accepted and successfully performed for the management of patients with multiple rib fractures. Several types of devices, such as titanium bar, plate, and screws, are used for rib stabilization. Titanium devices provide a strong support for rib fixation and chest wall reconstruction and are rarely associated with complications. Herein, we report an unusual case of mechanical failure associated with a broken titanium plate. A 47-year-old man was treated with surgical stabilization of rib fractures using titanium plates after blunt trauma leading to epidural hematoma and massive hemothorax. After decompressive craniectomy, bleeding control, and rib fixation for chest trauma, he developed hyperactive delirium, which was not well controlled. On the 17 day of operation, a chest radiograph showed a broken rib plate. Surgeons who perform surgical rib stabilization should be aware that titanium plates are vulnerable to breakage under some conditions, such as hyperactive delirium.