In a one-year prospective study of 42 elite orienteers, 73 recent injuries (1.7 per runner per year) were found. Acute injuries totalled 52% and 48% were due to overuse. Ankle sprains made up 37% of acute injuries while the remaining were mainly contusions caused by falls or bumps against branches or rocks. Medial shin pain, Achilles peritendinitis, peroneal tenosynovitis and iliotibial band friction syndrome were the most frequent overuse injuries. All overuse injuries were located in the lower extremity while 18% of acute injuries was located elsewhere. Acute injuries were most frequent in the competitive season while overuse injuries occurred most often during the continuous training period.