A prospective study was conducted on 55 consecutive patients to evaluate the efficacy of gallium scintigraphy in detecting malignancy in any soft tissue mass. It was determined that gallium scintigraphy could detect malignancy with a sensitivity of 96% and a specificity of 87%. Large and small sarcomas, irrespective of their fascial location, were identifiable by gallium imaging. Occult, nonpulmonary sites of disseminated disease were detected in 13%. Gallium scintigraphy proved to be a reliable predictor of malignancy for all soft tissue masses, but because of its cost, it must be used judiciously.