Over the last 10-15 years, there has been a dramatic increase in popularity of running marathons. Numerous articles have reported on injuries to runners of all experience, with yearly incidence rates for injury reported to be as high as 90% in those training for marathons. To date, most of these studies have been cohort studies and retrospective surveys with remarkably few prospective studies. However, from the studies available, it is clear that more experienced runners are less prone to injury, with the number of years running being inversely related to incidence of injuries. For all runners, it is important to be fully recovered from any and all injury or illness prior to running a marathon. For those with less experience, a graduated training programme seems to clearly help prevent injuries with special attention to avoid any sudden increases in running load or intensity, with a particularly high risk for injury once a threshold of 40 miles/week is crossed. In both sexes, the most common injury by far was to the knee, typically on the anterior aspect (e.g. patellofemoral syndrome). Iliotibial band friction syndrome, tibial stress syndrome, plantar fasciitis, Achilles tendonitis and meniscal injuries of the knee were also commonly cited.