The authors present a case of a very unusual clinical presentation of an intra-axial supratentorial glioblastoma multiforme (GBM) in a 63 year old diabetic female patient presenting with a three week history of left progressive complete oculomotor nerve palsy. CT scan and magnetic resonance imaging of the head revealed a left intra-axial mesial temporal glioblastoma multiforme. Operative resection and microscopic examination of a tissue specimen confirmed the diagnosis. The nature of the tumor, the pattern of spread and the postulated mechanisms of such a presentation are discussed. The authors suggest including the diagnosis of GBM in the differential diagnosis of patients with isolated complete oculomotor nerve palsy at the appropriate age group.