Epileptic activity can modulate reactions of the autonomic nervous system. Although there is some evidence of a differential left/right hemispheric influence on the cardiovascular system, diverse investigations have shown controversial results. In our study, complex partial seizures of patients with temporal lobe epilepsy were recorded using subdural electrodes, thus providing reliable information on the focus side. We analyzed the preictal and ictal heart rates of 27 patients, 16 revealing right and 11 revealing left temporal foci. During the seizures, both groups showed a significant increase in heart rate. Preictal tachycardia was only significant in the right focus group, whereas no significant change in heart rates could be detected in the left focus group. Our results confirm a right hemispheric lateralization of sympathetic cardiac control.