The clinical occurrence of isolated sphenoid sinusitis is rare. Due to a long history and few initial symptoms, diagnosis of this potentially fatal infections can be difficult. Radiological aspects in 10 patients are presented (e.g. type and design of examination and whether inflammatory or destructive changes could be shown), as well as clinical aspects (cranial nerve palsy, concurrent inflammation, duration of disease and therapy). CT proved to be superior in diagnosing the extent of any bony changes, while MRI was more useful in detecting inflammation.