BACKGROUND: Epilepsy patients may have a various whole gamut of psychological problems attending upon, in part or in whole, epileptic seizure focus. To investigate psychological problems related to epileptic focus and their postsurgical change, personality evaluation was performed in medically intractable epilepsy patients before and after the epilepsy surgery. METHODS: There were 103 temporal lobe epilepsy (TLE) patients with or without hippicampal sclerosis (HS) and 22 extratemporal lobe epilepsy (XTLE). We used MMPI as an objective method of assessing emotional state and personality profile of the patients. The preoperative MMPI scales were compared between the TLE group and the XTLE group, between TLE with HS group and without HS group (NHS), and right and left TLE groups. In addition, the postsurgical changes of MMPI scales were analyzed upon only 31 TLE patients who had preoperative and postoperative MMPI RESULTS: First of all, in terms of mean value of each scale, all results observed were within normal range. When these results were analyzed using t-test, the scores of social introversion were significantly higher in HS group than in NHS group. Secondly, there were significant postoperative decrease of depression, hypochondriasis, psychasthenia, schizophrenia scales in HS groups and mascu-linity-frminity scale in NHS group. There was no significant difference of MMPI scales between TLE and XTLE CONCLUSION: The results of this study that hippocampal sclerosis may affect the preoperative personality and the removal of pathologic hippocampus may improve MMPI scales.