We determined the incidence of soft-tissue/musculoskeletal injury occurring during 8,076 recruit-months at risk among recruits undergoing basic training at Marine Corps Recruit Depot, San Diego, California, between January and April 1990. We analyzed International Classification of Disease codes relating to initial visit for injuries, and calculated recruit-months from weekly strength figures. Training-related injuries occurred at a rate of 19.9 injuries per 100 recruit-months. Within the sports medicine clinic, iliotibial band syndrome (22.4%), patellar tendinitis (15.1%), and mechanical low back pain (11.4%) occurred most frequently, with rates per 100 recruit-months of 2.1, 1.4, and 1.1, respectively.