In order to clarify the CT findings of lethal midline granuloma(LMG) diagnosed clinically or histopathologically, the authors retrospectively analyzed 12 patients who were ween at Kyungpook National University Hospital from February 1985 to August 1989. CT showed nasal mucosal thickening and/or soft tissue mass( 9 cases), spreading of the lesions along the facial subcutaneous fat plane(8 cases), invasion into the paranasal sinuses(5 cases), bone destruction(5 cases) nasopharyngeal mass lesion(2 cases), and extension of the lesion into the infratemporal fossa(1 case). In spite of the fact that CT does not make definitive diagnosis of LMG, it permits evaluation of the extent of the lesion, detection of the combined lesion, differential diagnosis, and close monitoring of its evolution under treatment.