Benign osteoblastoma is an unusual primary bone tumor. It affects usually long bones or the vertebral column. Osteoblastoma affecting the calvarium is extremely rare. A 23-year-old man presented with a two-month history of swelling and tenderness in the right temporal region. Computed tomography revealed an expansile, lytic lesion in the left temporal bone. T1- and T2-weighted magnetic resonance (MR) images demonstrated an isointense lesion in the temporal bone. After gadolinium DTPA injection, MR images revealed dense enhancement. The histopathological findings proved that the lesion was a benign osteoblastoma. To date, very few cases of the benign osteoblastoma arising in the calvarium have been reported in the literature. We discuss diagnostic and management aspects of this uncommon tumor.