School football injuries were studied over the seven months of one season on 150 males aged 16.94 +/- 0.82 years. Training averaged 4.13 +/- 1.47 hours per week and matches 1.84 +/- 0.60 hours per week. Mean time injured was: 0.51 +/- 1.7 days in hospital, 34.27 +/- 37.08 days off sport and 13.98 +/- 5.22 days of restricted activity. There were 136 match and 63 training injuries giving 175.98 injuries per 10000 hours of matches and 31.06 injuries per 10000 hours of training. Injuries were treated as follows: hospital 83, general practitioners 51, physiotherapists 28, no treatment 38. The most common injuries were: ankle sprain (11.6% of the total), hamstring strain (6.5%), contusion (6.5%) back strain (6%) knee sprain (5.0%), finger sprain (5.0%), other muscle strains (5.0%), fracture of the wrist (5.0%), dislocation of the finger (4.5%), overuse injury of the back (4.0%), tenosynovitis (3.5%), fracture of the ankle (3.0%). Thirteen injuries were to goal-keepers, 85 to backs, 31 to mid-field players and 70 to forwards. In 34.83% of the injuries foul play was given as the major cause. This was followed by "Lack of fitness", "Poor kit or boots" and "Previous injury" (all 11.24%). The most common minor cause was "Poor state of the pitch" (17.42% of injuries).