Osteomas are benign bone-forming tumours. They are mostly seen in the frontoethmoidal region in the head and neck region, and occipital localization is extremely rare. They are often asymptomathic lesions, and can be detected by cosmetic complaint of the patient. In large tumours headache and dizziness can be the symptoms. A 39-year-old female admitted for gradual enlargement of a swelling on the left side of the back of her head, and nonspecific headache. In physical examination a bony hard, immobile, non-tender lesion on left occipital bone was detected. Neurological examination was normal. In brain computed tomography, a bony mass of 3.5 cm in diameter and 1 cm thick was revealed. Magnetic resonance imaging revealed a well-circumscribed hypointense lesion with dimensions of 3x3,5x1 cm which caused a slight compression on the parenchyma of the left occipital region. Lesion was totally excised to relieve cosmotic deformity. Histopathological examination revealed it to be an osteoma. Before surgery differential diagnosis, and extension of the lesion should be carefully explored. We reported this case. Because of rarity of occipital localization.