STUDY DESIGN: We retrospectively reviewed nine patients of lumbar extraforaminal disc herniation which underwent conservative or surgical treatment. OBJECTIVES: We evaluated the clinical characteristics, accuracy of diagnostic methods, and result of conservative or surgical treatment for the lumbar extraforaminal disc herniation. SUMMARY OF BACKGROUND DATA: Lumbar extraforaminal disc herniation represents an important component of lumbar disc herniation because of the difficulty in diagnosis and the difference in clinical characteristics and surgical approaches in contrast to usual intracanalicular disc herniation. MATERIALS AND METHODS: Nine patients which we have experienced from March 1994 to February 1997 were evaluated by physical examination, magnetic resonance imaging, EMG, and disco-enhanced computed tomogram. There were 4 males and 5 females, and average age was 42.4 years. RESULTS: The level of herniation was 4 cases at L4-5 and 5 at L5-S1. Radiating pain was chief complaint but low back pain was absent or mild. Accuracy of disco-enhanced computed tomogram was superior to that of magnetic resonance imaging. The results of conservative treatment were good in 2 cases(40%), fair in 2 cases(40%), and poor in 1 case(20%). And those of surgical treatment including partial laminectomy, medial facetectomy, and discectomy or extraforaminal approach were excellent in 3 cases(75%), good in 1 case(25%) according to the grading of MacNab. CONCLUSIONS: Lumbar extraforaminal disc herniation represents compressive symptoms of upper lumbar root of the involved level characteristically. Location and degree of disc herniation is an important tractor for determining the surgical approach, and disco-enhanced computed tomogram is a definite diagnostic method.