A study was done of 13 cases of biopsy-proved Paget disease in which the disease involved the anterior tibial tubercle with extension into the metaphysis and diaphysis, but without apparent involvement of the proximal tibial epiphysis. Case data were obtained from archives containing more than 350 cases of Paget disease. Age, sex, symptoms, serum alkaline phosphatase level, and histologic and radiographic appearance of the lesions were evaluated. Patients were young at clinical presentation, averaging 36 years of age. In five of six patients the serum alkaline phosphatase level was normal. The proximal extent of the disease was the anterior tibial tubercle rather than the proximal epiphysis. Radiographic patterns ranged from predominantly lytic to mixed lytic and blastic to predominantly blastic, and the lesion was marginated by a flame-shaped configuration. The radiographic appearance of Paget disease of the anterior tibial tubercle is characteristic and should be sufficient to suggest the diagnosis and preclude biopsy.