From its roots in San Diego to its Olympic debut in Sydney in 2000, triathlon has emerged as a popular sport with a wide variety of participants. Because of the nature of the sport, excessive training resulting in overuse injuries is common. Triathlon injuries can also be unique from the individual sports involved in that they are attributed to a cumulative effect of multi-sport training. Because many triathletes have not grown up participating in the individual sports, biomechanics in each of the disciplines must also be considered as a source of injury. Nutrition and environmental factors and the role that they play in the endurance athlete should also not be overlooked. The sport of triathlon is rapidly growing, and the ability to recognize the unique aspects of these injuries can help the multisport athlete to train properly and be healthier and more successful.