A 5-year experience with 12 sternal fractures treated at the Los Angeles County Harbor/UCLA Medical Center is presented. Our data indicate that sternal fractures with roentgenographic mediastinal widening commonly have associated aortic injuries. There is an almost uniform depression of right ventricular or anterior left ventricular function associated with sternal fractures and these cardiac sequelae are documentable by first-pass biventricular radionuclide angiography including left ventricular segmental wall motion analysis. These data facilitate the management of patients with complex hemodynamic problems. In contrast, the incidence of displaced or unstable fractures is very low. Only one patient in this series had a depressed manubriosternal fracture, and no injury necessitated surgical stabilization. The outcome of isolated sternal fractures is benign, and they should be viewed as harbingers of the discovery of other injuries.