Hippocampal abnormalities correlated with mesial temporal sclerosis (MTS) are well documented. MTS may be associated with extrahippocampal anomalies involving limbic structures along a known neuroanatomic pathway (Papez circuit). We report a patient with MTS and thalamic changes. Seizure-related thalamic damage could have been caused by abnormal electric discharges from the mamillary body to the anterior thalamus through the mamillothalamic tract. This suggests that MTS is not limited to the temporal lobe but could represent a limbic system pathology.