Osteoblastoma is a rare, solitary benign tumor that is usually situated in axial skeleton mainly in vertebra. It is rarely seen in ethmoid and frontal sinuses. A 40-year-old man who had osteoblastoma originated from frontal and ethmoidal sinuses that extends up to frontal lobe and gave rise to personality disorders by compressing the frontal lobe, and caused superior gaze palsy by compressing the superior rectus muscle. We present this rare case with clinical, radiological and histopathological findings.