The benign condition of isolated first rib fracture is compared with the severity of intrathoracic injuries resulting from first rib fracture associated with multiple rib injuries. Seventy-five patients with 90 first rib fractures were divided into two groups. Group 1 (n = 13) included those with isolated first rib fractures and Group 2 (n = 62), those with first-rib fractures associated with multiple rib injuries. In Group 1 patients, intrathoracic injuries were mild with no major vascular injuries. Conversely, Group 2 patients sustained severe intrathoracic injury, 58% of them with aortic injury. Stress is placed on early diagnosis, assigning of priority to associated injuries, and early operative intervention.