We have been studying 17 cases for operated mucoceles over a period of 4 years. Usual predisposing factors are often present, however we found no underlying malignant tumor revealed by a mucocele. Surgical treatment always included exclusion and filling with bone grafts in case of frontal involvement. Small ethmoidal lesions without symptom found on the CT scan are worrying because of their potential deterioration; in such cases, our attitude has been surgical.