An occupational accident is an accident that people suffer at work. It is an occurrence that the victim had not planned or expected. An occupational accident may also be an act of violence in connection with or arising out of work. The accident results in at least one worker dying, becoming ill, or suffering an injury. Work-related injury and disease is an important cause of injury and disease at national and global levels. The injury burden is more easily recognized, but the disease burden is probably much higher. Generally, more reliable information is available on injury than on disease, and on fatal cases than on nonfatal cases. Most cases of work-related injury or disease should be preventable. Understanding the scope of the problem and how and why work-related fatal and serious nonfatal, disorders occur is an important first step in their prevention.