We studied the value of histopathological grading in determining the prognosis of giant cell tumour (osteoclastoma) and the rate of local and distant recurrences in a consecutive series of 31 patients. We found that grading had no prognostic value. Eighteen patients were treated by intralesional curettage and 13 by wide excision. Ten patients (56%), who were all treated by curettage, had local recurrences, but none of the tumours with wide excision recurred (p < 0.05). Five (16%) had local recurrences as well as distant metastases, usually to the lungs. The recurrences developed later than an average of 12 years after primary treatment in 3 patients. Wide excision and life-long follow up should be considered in the management of these tumours.