OBJECTIVE: To study the injury characteristics in professional football and to follow the variation of injury incidence during a match, during a season and over consecutive seasons. DESIGN: Prospective cohort study where teams were followed for seven consecutive seasons. Team medical staff recorded individual player exposure and time-loss injuries from 2001 to 2008. SETTING: European professional men's football. PARTICIPANTS: The first team squads of 23 teams selected by the Union of European Football Associations as belonging to the 50 best European teams. MAIN OUTCOME MEASUREMENT: Injury incidence. RESULTS: 4483 injuries occurred during 566 000 h of exposure, giving an injury incidence of 8.0 injuries/1000 h. The injury incidence during matches was higher than in training (27.5 vs 4.1, p<0.0001). A player sustained on average 2.0 injuries per season, and a team with typically 25 players can thus expect about 50 injuries each season. The single most common injury subtype was thigh strain, representing 17% of all injuries. Re-injuries constituted 12% of all injuries, and they caused longer absences than non re-injuries (24 vs 18 days, p<0.0001). The incidence of match injuries showed an increasing injury tendency over time in both the first and second halves (p<0.0001). Traumatic injuries and hamstring strains were more frequent during the competitive season, while overuse injuries were common during the preseason. Training and match injury incidences were stable over the period with no significant differences between seasons. CONCLUSIONS: The training and match injury incidences were stable over seven seasons. The risk of injury increased with time in each half of matches.