Bicycle-related head trauma is a significant source of death, disability, and health-care costs in the United States. Bicycle helmets are effective safety devices that can reduce most of this burden on society. Bicycle helmet laws and education programs are effective ways to increase helmet use rates. Osteopathic physicians can play a prominent role in bicycle-related injury prevention by actively supporting and participating in helmet legislation, research, and community-based education. This article provides a current summary of state bicycle helmet laws and highlights research that supports the effectiveness and necessity of these laws. The recent trend in safety standards for bicycle helmets is included to give a comprehensive view of bicycle helmet law in the United States.