Fibrous dysplasia is a condition where fibrous tissue and bone with an altered structure replace normal bone. The craniofacial involvement is difficult to treat due to location, uncontrolled proliferation and compression of nerves. These result in facial asymmetry, pain, cranial nerve deficiencies, loss of vision or hearing, alterations in breathing, etc. The use of pamidronate, which inhibits the resorptive activity of osteoclasts may be an alternative to surgical intervention and may improve the results of treatment.To evaluate the treatment of monostotic craniofacial fibrous dysplasia with pamidronate.A prospective pilot study was undertaken in 6 children with progressive fibrous dysplasia located in the mandible (3 pts), maxilla (2 pts) or cranial base (1 pt). Surgery consisted only of a biopsy and implantation of gentamycin sponge into the biopsy bed in 3 cases in which an infection was initially suspected. All patients received pamidronate infusions (1mg/kg i.v. for 3 days, every 4-6 months). The changes in bone density and extension of the disease were evaluated by serial orthopantomograms and CT scans. Follow up time was 9-24 months.Pain relief was achieved in all cases, decrease in swelling in 3, and stabilization in 3 cases. Radiological investigation revealed any progression but reduction in size and calcification of osteolytic lesions. The local bone density increased and there was no further spread of the disease in any of the patients. Inflammatory symptoms resolved in all cases. The only side effect was an increase in body temperature up to 38-40 degrees C.Pamidronate appears to be an effective and well-tolerated therapeutic option for patients with fibrous dysplasia. In the future, the combination of the metabolic blockage of the dysplasia by pamidronate and limited non-mutilating surgical interventions are possible.