One hundred thirty-one patients with 169 stress fractures were treated between January 1984 and January 1990. The highest incidence was in teenage girls (25.5%), and the predominant sites were tibia (31.5%) and femur (12.5%). The mean interval between the start of hard training and the onset of symptoms was 2.7 months and the mean amount of increased activities was 93.7%. Volleyball (24.3%) and running (17.3%) had the majority of incidents, and 95 (72.5%) patients were professional athletes. Radionuclide bone scans were needed in 61 (46.6%) patients and 16 (12.2%) showed multiple lesions. Asymptomatic stress fractures were found in 12 (9.2%) patients, and only five showed recurrence at the other sites. Eleven (6.5%) cases were treated operatively, and involved the tarsal navicular (2.9%) and femur (2.4%).