Based on the results of the present comparative study between two different age-groups, soccer may be considered as a relatively low-risk and safe sport in young players, with an injury pattern just slightly different from the seniors and with only a few severe injuries. The present study supports the view that adult players are more frequently injured than youngsters, which is in accordance with results of previous studies. Youth games are probably less aggressive with less stress than in adult games (Schmidt-Olsen et al., 1991). Concerning the type of injury, the proportion of acute and overuse injuries was also similar to findings reported in other studies for adult players. The majority of soccer injuries are acute and the proportion connected with overuse varies from 9% to 34% (Nielsen and Yde, 1989; Arnason et al., 1996). The fact that, in adult players, chronic injuries exist, is related to the nature of soccer. Various overuse injuries of the knee are reported to be common in soccer (Schmidt-Olsen et al., 1991). These include quadriceps and patellar tendinitis, illiotibial tract syndrome and patellofemoral syndrome.