Stress fractures of the tarsal navicular do not heal predictably with conservative treatment, so we recommend operation if the fracture remains symptomatic, and radiographs show wide separation of a complete fracture, extension of an incomplete fracture, delayed healing, or a medullary cyst. An autologous bone graft is inserted after en-bloc resection of the fracture surfaces. It is important that the fracture is fully exposed to its distal limits before the graft is inserted. We have grafted 19 fractures in 18 patients. Six fractures were complete, 12 incomplete and one had a residual medullary cyst. Of the 15 patients with adequate follow-up, 12 had been able to return to a pre-injury level of activity by five to 12 months.