Although the safety value of automobile seatbelts has been proven, the seatbelt is capable of producing serious injury to the spine and intraabdominal contents during an abrupt deceleration crash. Ten cases of injury to the spine, pelvis, and abdomen are added to the expanding literature on seatbelt injuries. At least 40 cases of serious injury to the spine have been reported with the lap seatbelt. The trauma to the spine is produced by severe flexion of the torso over the belt, causing a tearing of the posterior elements, with less involvement of the vertebral bodies. One of the interesting intermediate forms of vertebral injury is the Chance fracture: a horizontal splitting and separation of the posterior vertebral arch, involving the pedicles, lamina, transverse processes, and spinous process, with variations. Following seatbelt trauma to the abdomen, the most common injury is perforation of the small bowel with associated trauma of its mesentery. Injury to almost every hollow and solid viscus in the abdomen has been reported, and multiple injuries are common. Combined injuries of the spine and intraabdominal contents occur. Knowledge of the type of injury produced by seatbelts will lead to more prompt and accurate diagnosis of the extent of injury. The history of flexion oven the seatbelt, or the observation of a seatbelt contusion, is most important. Good quality roentgenograms of the spine in multiple projections, and occasionally tomograms, are of great value. Oral water soluble contrast media can be helpful in the diagnosis of intestinal perforation, since free air is difficult to demonstrate in these seriously ill patients. The diagonal belt and the combination lap-and-diagonal belt have produced injury to the sternum, ribs, and upper abdomen. The diagonal belt prevents the lumbar flexion fracture seen with the lap belt, but may produce a flexion type injury in the neck. The shoulder harness used with the lap belt should be evaluated to replace the lap-and-diagonal belt, along with other structural improvements in automobile safety design.