Current knowledge about the aetiology of the soccer injuries is limited. The presumed complex interaction of various risk factors requires in-depth statistical analysis of techniques to identify dependent and independent variables, and to describe the extent, direction and strength of the relationship between the independent predictor variables and soccer injuries. However, in the majority of the studies, the application of statistical analysis was restricted to descriptive and univariate analysing techniques. Moreover, the results of studies on the aetiology of soccer injuries are biased by selection according to age, gender and level of competition. Identified intrinsic risk factors are joint flexibility including pathological ligamentous laxity and muscle tightness, functional instability, previous injuries and inadequate rehabilitation. Extrinsic risk factors include the exercise load in soccer (competition and practice), inadequate equipment (shinguards, taping, shoes), playing field conditions and foul play. Also, the number of well controlled experimental studies on the prevention of soccer injuries is very limited. In different selected homogenous subgroups of the soccer population in Sweden and Denmark, different types of prevention proved to be successful in reducing the incidence and severity of soccer injuries. Selection bias should be considered in the interpretation of these results. Generally, the epidemiological information of the sport medical aspects of soccer injuries appears to be inconsistent and far from complete. The aetiology of soccer injuries may differ between different subgroups of the soccer population. As a consequence, different subgroups of soccer players may need different prophylactic programmes to achieve a major reduction in incidence and severity of soccer injuries. More research is needed to identify high risk groups and independent predictor variables of injury within those subgroups. The outcome of these studies must lead to the development of effective prophylactic programmes. Preferably, such studies should include uniform definitions of injury and should be based on sound epidemiological methodological principles.