Fibrous dysplasia is a benign, nonfamilial disorder of the skeleton, characterized by expanding fibroosseous lesions occupying single or multiple bones with possible extraskeletal anomalies. Fibrous dysplasia begins in childhood and is not usually recognized until adolescence or adulthood. When fibrous dysplasia affects the foot, it is often the expression of the polystotic form of the disease. This paper will review the pathology of the disease and monostotic involvement of the first metatarsal.