In 2008, approximately 60 million children, adolescents, and young adults were involved in organized sports, which account for more than 3.5 million injuries each year. Family physicians often create and implement return to play (RTP) protocols for athletes. If a concussion is suspected in an athlete, the athlete should be withdrawn immediately from participation in sports and monitored with serial assessments. There is no same-day RTP for athletes with concussion. A brief period of physical and cognitive rest is suggested, with a gradual return to activity. Transient brachial neuropraxia, also known as a burner or stinger, results from injury to the brachial plexus and typically resolves within days. Strict protocols exist for college and high school athletes with bacterial, viral, and fungal skin infections. Athletes may RTP when no new active lesions are present, healing lesions are covered, and the athlete is receiving treatment. Provision of care at a mass participation event requires extensive preparation. Emergency action plans are an invaluable tool for large sports events. These should be jointly developed by all involved parties and rehearsed regularly. Legal, liability, and privacy considerations may affect the physician's decision to provide care at a sports or mass participation event.