Accurate preoperative diagnosis of petrous apex lesions is critical because thesurgical approaches used for this region are different depending upon the specific diseaseprocess involved. While CT and MRI have each improved the accuracy of preoperativediagnosis of petrous apex pathology, these imaging studies are most helpful when usedin conjunction with one another. When systematically applied, the combination of CTwith contrast and MRI (with and without gadolinium) permits accurate differentialdiagnosis of primary petrous apex lesions. This review presents the imaging approachemployed at the House Ear Clinic for the differential diagnosis of primary lesions of thepetrous apex.