BACKGROUND Osteoma is a benign tumour, composed of mature compact or cancellous bone, which can arise in any facial bone. Among the paranasal sinuses, the frontal and ethmoid sinuses are most frequently involved. Osteoma grows very slowly and small lesions are often not symptomatic. On the other hand, sometimes patients present with symptoms such as sinusitis, headache or ophtalmologic manifestations. These findings are secondary to obstruction of the involved sinus cavity with secondary mucocele formation or occasionally an expansile lesion with distortion of the facial contour. METHODS From 2005 to 2010, twenty-one (21) patients affected with non-syndromic fronto-ethmoidalosteomas were evaluated in our Department. Collected data include patients' age at the time of disorders, gender, presenting signs and symptoms, primary diagnosis, type and characteristics of the treatment performed, radiological findings and post-treatment results. All patients were investigated by CT scans in axial and coronal planes. The treatment and outcomes of this group were reviewed. RESULTS All patients of the study underwent surgery and had a follow-up of at least 5 years. Surgical excision of the tumour was undertaken. Postoperative CT scans in axial and coronal planes showed complete removal of the tumour in all cases. No complications or recurrences were observed. CONCLUSIONS Small, asymptomatic osteomas probably do not need to be treated but should be observed periodically. Surgical management remains the mainstay of treatment for these tumours. It requires total excision via an adequate approach, depending upon the site of presentation. CONCLUSIONS A purely endoscopic endonasal approach has the risk of incomplete excision. In our experience open technique provides a wide exposure and better control. Even frontal osteomas can be safely removed by careful open surgery BACKGROUND Ethmoidal sinus, Frontal sinus, Open treatment, Osteoma, Paranasal sinuses.