PURPOSE: The Wechsler Memory Scale-III (WMS-III) including new visual memory tests was developed to overcome the limitation of WMS-Revised (WMS-R). We examined the utility of the WMS-III in predicting laterality of memory impairment in patients with mesial temporal lobe epilepsy (MTLE). METHODS: We included 49 consecutive patients with unilateral MTLE who had left hemisphere dominance for language by WADA test and underwent temporal lobectomy. Methods of analysis included evaluation of group means on the various indexes and subtest scores of WMS-III, the use of ROC curves, an examination of Auditory-Visual Index (AVI) discrepancy scores and correlation analysis between AVI discrepancy scores and age, onset age of patients. RESULTS: 1) Patients with left MTLE had significantly lower scores on several scores and indexes compared to those with right MTLE. 2) In analysis of ROC curves, the area under the curve and the suggested cutting score were 0.696 and 4 (a sensitivity 0.704, a specificity 0.727) for immediate AVI discrepancy score and 0.702 and 5 (a sensitivity 0.556, a specificity 0.773) for delayed one, respectively. 3) In right MTLE, there was a tendency for linear correlation between AVI discrepancy scores and age at onset. CONCLUSIONS: Overall, WMS-III has limited value in identifying particular memory deficits associated with either left or right temporal lobe dysfunction. AVI discrepancy scores may be more useful to predict right hemispheric dysfunction rather than left ones.