Soccer causes the largest number of injuries each year (18% of all sports injuries) in the Netherlands. The aim of this dissertation is to contribute to the body of evidence on injury prevention for adult male soccer players. Chapter 1 is a general introduction and presents the “sequence of prevention” model proposed by Van Mechelen et al. (1992). From the review described in chapter 2 we concluded that there is conflicting evidence for the effectiveness of exercise-based programmes to prevent soccer injuries. These generic preventive training programmes involve different exercises focusing on multiple joints and/or muscle groups and aim to prevent of the most common soccer injuries. We believe that the general structure of such programmes can be useful for numerous adult male soccer teams, because they are cost-free and can often be easily incorporated in regular training sessions. Chapters 3 to 5 then describe the study design and results of our randomized controlled trial (RCT) investigating the effectiveness and cost-effectiveness of FIFA’s “The11” programme for Dutch adult male amateur soccer players. After one season, we did not find significant differences in the overall injury incidence or injury severity between the intervention and control groups, although the intervention did result in a cost-saving effect. In conclusion, there are doubts that The11 is an effective programme to prevent soccer injuries in this particular population of adult male amateur soccer players. Based on the model by Van Mechelen et al., and having found no preventive effect of The11 on injury incidence among male amateur players, we used the data we had collected to establish the extent of the injury problem for this particular group and to gain more insight into injury characteristics. Chapter 6 presents the main findings of this study: almost 60% of Dutch amateur soccer players sustained at least one injury during one competitive soccer season, and approximately one third of these injuries resulted in absence from soccer play for at least one month. Chapter 7 provides information on injuries in Dutch professional soccer players. In chapter 8, the injury data from the professional and amateur cohorts are compared. The overall injury incidence was higher in the amateur cohort, as was the incidence during training. In contrast, the injury incidence during matches was higher among the professional players. Soccer injuries result from a complex interaction of multiple risk factors and events. Many risk factors are mentioned in the literature, but the findings are contradictory. We therefore conducted a literature review to study risk factors for hamstring injuries in male adult soccer players (chapter 9). We concluded that previous hamstring injury is the strongest predictive factor for hamstring injury. Conflicting evidence was found for age and hamstring length or flexibility as risk factors for hamstring injuries. Finally, chapter 10 offers a general discussion, reflecting on the main findings of our studies. The chapter ends with several recommendations for future research.