An unusual case of sphenoethmoidal sinusitis complicated by cavernous sinus thrombosis, meningitis and pontine and cerebellar infarction is described. The patient presented with advanced intracranial complications which in retrospect caused delay in recognition and treatment of the underlying sphenoethmoidal sinusitis. Surgical drainage of the sinusitis was ultimately required. The pathogenesis of these complications is discussed, and the topic of sphenoid sinusitis reviewed in order to emphasize the numerous neurological manifestations of this disease.