With the appearance of MR, a great advance has been made in the study of the aetiology of epilepsy. This technique can show anomalies not detected in CT scans, obtain images of multiple planes, improve the differentiation of cerebral tissues and allow improved visualization of the temporal lobe, making it very useful in the study of patients with complex partial crises (CPC). We studied 151 epileptics with CPC by means of CT scan and MR in all cases; the anomolous topography was the same in all cases, but the diagnosis was not. In patients with a previously normal CT scan, on MR anomalies were detected in 24 cases. We found a statistical differences on evaluation of the MR anomaly depending on whether the CT scan was normal or abnormal. Statistical differences were also found when there were a greater number of anomalies on MR depending on the frequency of crises at the onset of the disorder.