After the first report on bisphosphonates related osteonecrosis of the jaws in 2003, numerous papers have been published concerning this pathology. Medical practitioners are faced with the difficult task of managing this new disease. The therapy is time consuming. A good planned prophylaxis is very important. In advanced stages, if conservative treatment (antiseptics and antibiotics) fails, then surgical treatment is indicated. This paper reports 2 cases with maxillary sinusitis related to bisphosphonates therapy.