The purpose of this prospective study was to examine the incidence, nature, causes, and severity of injuries in female floorball. Three hundred and seventy-four licensed female floorball players from Finnish top leagues were observed prospectively for one season (6 months). The practice and game hours of floorball were recorded on an exercise diary. All injuries were registered with a structured questionnaire and verified by a physician. During the study period, 133 out of the 374 (35%) players sustained 172 injuries. The injury incidence was 1.8 per 1000 practice hours and 40.3 per 1000 game hours. Of all injuries, 70% were traumatic and 30% were from overuse. The most common injury type was joint sprain (27%). The most commonly injured sites were the knee (27%) and ankle (22%). Twenty-one of the knee injuries (46%) were serious including 10 anterior cruciate ligament (ACL) ruptures. Eight of ACL ruptures occurred during floorball games, giving an ACL rupture incidence of 3.6 per 1000 game hours. Eleven injuries (6%) needed hospital admission. The study attested that injury rate in floorball game is very high. Injury prevention strategies in female floorball should be targeted at injuries occurring at the knee and ankle.