To identify the risk factors of injuries in handball, 221 players were followed during one indoor season. The injury incidence was 4.6/1000 playing hours and 11.4/1000 game hours. The upper extremity was involved in 41% of the injuries including 21% finger sprains. Ankle sprains were the most common injury (33%), and overuse injuries accounted for 18%. The risk of reinjury was 32%. Contact with opponent players during running or shooting caused 31% of the injuries. Errors during grasping the ball were the reason for most of the finger injuries. Forty percent of the injuries was treated by the players themselves. After the injury 73% were absent from handball for more than 1 week. Forty-one percent of the injured players had complaints 6 months after the end of the season. The study shows that injuries in handball are serious and cause extensive consequences for the players. In most of the injuries both intrinsic and extrinsic factors were involved, and prophylactic intervention in these cases demands changes in more fields.