Bisphosphonates are compounds used in the treatment of various metabolic and malignant bone diseases. In the last 2 years there has been a significant increase in referrals to the Department of Oral and Maxillofacial Surgery of patients with exposed necrotic jaw bone, diagnosed elsewhere as chronic refractory osteomyelitis of jaws, mostly after several teeth extractions. The only clinical feature in common for all the patients was the use of bisphosphonates in the treatment of bone diseases. A retrospective study was performed of 11 patients with necrotic bone lesions of the jaws of various extents referred to this Department from July 2003 to November 2004. The management of the patients included cessation of bisphosphonate therapy for 2-8 months and various surgical restorative procedures thereafter. Four patients (36%) presented with maxillary bone involvement, 6 (55%) had mandibular bone necrosis and 1 (9%) presented with necrosis at 3 quadrants. All patients had received bisphosphonate therapy for 6 months to 5 years. Biopsies from the necrotic lesions revealed no metastatic disease. One patient who was removed from bisphosphonate therapy for 8 months recovered completely, one other who was not removed from bisphosphonate therapy relapsed and for all the others, with cessation of bisphosphonate therapy for 2-6 months, the results were inconsistent. A new complication of bisphosphonate therapy administration, i.e. osteonecrosis of jaws, seems to be developing. The improved results after cessation of the medication should make clinicians reconsider the merits of the rampant use of bisphosphonates, while further investigation is needed to completely elucidate this complication.