A 78-year-old lady, with no history of trauma, was admitted with gradually increasing pain in the right groin and thigh; she had been unable to weight-bear for 24 h. The patient also complained of intermittent left shin pain. She had been treated for carcinoma of the breast 22 years earlier by total mastectomy with axillary clearance followed by local radiotherapy; she showed no signs of recurrence. The plain X-ray revealed a pathological fracture of the right proximal femur with a large osteolytic lesion. The left tibial radiograph showed extensive osteolytic lesions. The patient underwent palliative internal fixation of both the femur and the tibia. The histopathological report from the right femoral biopsy revealed a primary leiomyosarcoma and from the left tibia revealed a bony metastasis from a breast primary. Further investigation excluded any extraskeletal leiomyosarcoma. Primary leiomyosarcoma is a very rare tumour involving long bones in adults; only a few cases have been reported in world literature. The breast tumour gave rise to a bony metastasis 22 years after ‘cure’ and without local recurrence, which is again very uncommon. Such a combination is previously unreported.