Ballet dancers are athletes susceptible to ligamentous and bony injury. We reviewed retrospectively the bone scans (technetium-99m methylene diphosphonate) of 23 ballet dancers with pain in the back and/or lower extremities to determine the usefulness of scintigraphy in the detection of stress lesions of bone. The scintigraphic studies in 19 dancers identified multiple areas of stress injury in both symptomatic and asymptomatic locations. Thirteen dancers had 22 stress fractures (microfractures of trabeculae with associated bone repair) manifested by an intense focus of increased uptake of radiopharmaceutical, and 19 dancers had stress reactions (areas of accelerated remodeling and resorption of bone) demonstrated by diffusely increased uptake of radiotracer. Ten of the 13 dancers with stress fractures were symptomatic and six of the 19 dancers with stress reactions were symptomatic. The radiographs of 10 dancers with positive bone scans were normal or showed no distinction between acute and chronic injuries. Stress fractures were most prevalent in the feet, and stress reactions were most prevalent in the tibiae. The study confirmed that ballet dancers sustain significant bone stress in their legs and feet. Our results show that scintigraphy can be used to detect stress fractures and stress reactions at both symptomatic and asymptomatic sites in this population.