This population-based study aimed to analyse the demographic, clinical and histological features of patients with a malignant primary bone tumour of the femur presenting with a pathological fracture. Eighty-four patients were identified from a prospectively gathered national tumour database between 1960 and 2004. Demographic data, presenting features, tumour location, histological diagnosis, treatment, local recurrence, metastasis and survival data were gathered. An estimate of the annual incidence was obtained using population data from the General Register Office and was 0.4 per million population per annum. The mean age was 56 years (range 4-87 years) with a bimodal distribution and 46% were men or boys. Forty-one percent of patients presented with a history of trauma. The average duration of symptoms before presentation was 1-3 months. The most common histological diagnoses were osteosarcoma (14 patients) and Paget's sarcoma (12 patients). The local recurrence rate was 38% and the overall five-year survival was 22%. The prognosis was made worse by local tumour recurrence, the development of metastasis and age at diagnosis greater than 21 years. Limb salvage surgery did not alter the prognosis. Patients who present with pathological fracture of a primary malignant bone tumour, carry a poor prognosis in all tumour types and no improvement in survival was identified over the period of the study.