Purpose : To evaluate MR imaging findings of ossified posterior longitudinal ligament(OPLL) in the cervicalspine. Materials and Methods : Retrospectively, simple radiography(n=34), CT(n=9), and MRI(n=11) of 34 patientswith OPLL were reviewed. We evaluated the number of involved vertebral segment, morphologic type of lesions onaxial and sagittal imaging, spinal canal narrowing on the involved intervertebral disk level, intervertebralforaminal narrowing, relationship between spinal cord compression and morphologic type, and signal intensity onMRI. Results : Average number of involved vertebral segment was 2.65(9034). Most commonly involved vertebrallevel was C3--C4. On sagittal image, the lesions were classified to be continuous type(n=15), segmental type(n=7),mixed type(n=4), and circumscribed type(n=7). The most common type was continuous one(42%). On axial image, thelesions were classified to square type(n=13), mushroom type(n=18), hill type(n=13). The most common type wasmushroom one(41%). Forty-five percent(20/44) showed spinal stenosis which exceeded 25% of anteroposterior diameterof spinal canal. Twenty-three percent(19/81) of the case showed intervertebral foraminal narrowing. T1- and T2-weighted MRI showed low signal intensity in every 11 case. Two cases showed focal high signal intensity within lowsinal intensity lesion on T1 weighted images. Conclusions : The ossified lesion of OPLL could be evaluated withsimple radiography and CT. MRI displayed spinal cord compresion, intervertebral foraminal narrowing, andassociated vertebral disease which maybe useful in preoperative evaluation of symptomatic patients.