The combination of fibrous dysplasia and aneurysmal bone cyst of the skull base is extremely rare yet it should be recognized, lest the rapid growth of the lesion and the radiological picture lead to the wrong diagnosis of a malignant process. We report on a 6½-year-old patient who suffered from concomitant fibrous dysplasia and aneurysmal bone cyst of the skull base. He is still disease-free 4 years postoperatively. The treatment of choice remains early surgical removal of the maximal amount of involved bone that can safely be achieved. There is no role for radiotherapy in the treatment of these lesions. A review of the literature is included.