Background Participation in sports has beneficial effects on health. Unfortunately there are also negative effects due to sports injuries. The number of sports injuries in the Netherlands is about 3.6 million every year. A lot of those injuries occur during soccer. TNO developed a web-Based Injury information System (BIS) to study sports injuries. Objective To study the incidence, location, severity and risk factors of professional soccer and futsal injuries. Design In soccer a prospective cohort study was carried out by means of web-based information gathering. Data on background, injuries and recovery were registered during the season by the medical staff. A retrospective cohort study was carried out in futsal. Same data were collected by means of a self-administered questionnaire for the players. Setting Three cohorts of players were followed during one season: professional male soccer (2007), professional female soccer (2007–2008) and premier league male futsal (2009–2010). Participants 1.039 elite male soccer players, 118 elite female soccer players and 77 elite male futsal players. Outcome measurements Incidence, location, type, re-injury, overuse/trauma, duration of injuries. An injury was defined as physical complaints caused by soccer/futsal and resulting in a time loss from soccer/futsal of at least 1 day. Results Male soccer: 965 injuries, incidence 5.9, knee 20%, sprain/ligament 20%, 15% re-injury, 67% trauma, average duration 34 days. Female soccer: 125 injuries, incidence unknown, knee 22%, sprain/ligament 32%, 16% reinjury, 73% trauma, average duration 21 days. Male futsal: 58 injuries, incidence 3.1, ankle 38%, sprain/ligament 38%, 41% re-injury, 74% trauma, duration: 27% more than 4 weeks. Conclusions The rate of injuries among professional (fe)male soccer and premier league male futsal is high. Results for male and female soccer are in general comparable but different from results for futsal. BIS provides sports leagues with information that might help to improve their prevention management.