Several large clinical series have demonstrated that benign and malignant tumors occur in the foot and ankle at a much higher rate than previously thought. Vigilance is warranted in investigating any foot mass, including those with an apparently indolent course. Although tumors in the foot tend to produce symptoms relatively early because of the foot's compact structure, many tumors are initially misdiagnosed. Given the comparatively small size of the anatomic compartments in the foot, tumors often present outside the original compartment, making timely diagnosis essential. Major treatment errors can be avoided if physicians consider the potential for malignancy when evaluating all foot masses. A high index of suspicion, an organized approach to diagnosis, and evaluation of and adherence to the basic principles of treatment of musculoskeletal neoplasms increase the likelihood of acceptable results.