The dura provides an excellent protection against infiltration by malignant tumours. It is extremely rare for glial tumour cells to infiltrate the dura and subsequently invade adjacent structures. We report an interesting case of glioblastoma of the temporal lobe with spontaneous transdural spread to the skull base and infratemporal fossa. This is the first radiologically documented case of transdural spread of glioblastoma before and after the spread without previous craniotomy.