Idiopathic focal epilepsies and particularly rolandic epilepsy are considered to have an excellent outcome with spontaneous recovery during adolescence. The characterization of this syndrome in 1959 by Beaussart and Nayrac was a great progress for childhood epileptology: the existence of a focal epilepsy with a good prognosis and no underlying brain lesion, so-called "benign" epilepsy, was recognized. Since the first descriptions, numerous neuropsychological studies were performed showing variable results. All the studies agree with the fact that children with rolandic epilepsy keep a normal global intellectual efficiency and a good long-term outcome. Nevertheless, some children may suffer transiently during the active phase of the epilepsy from oromotor dysfunction, neuropsychological deficits, or attention deficits with learning disorders. The analysis of cognitive and neurophysiological correlations evidenced a significant correlation between the epileptic focus localization and few specific dysfunctions. We evidenced mainly a significant effect of the persistence of a prolonged slow focus and a strong activation of night EEG spike and waves on cognitive decline and attention disorders. These abnormalities are mainly observed during severe or atypical evolutions of rolandic epilepsy. Preliminary longitudinal studies show that these cognitive deficits are transient. Thus, the presence of an active epileptic focus, without underlying brain lesion, could interfere with normal maturation of cognitive function.