Epilepsy surgery has gained a large role in the treatment of intractable seizures in the last few decades because of the development of operative techniques and better identification of the cerebral anomalies using electrophysiological recordings and neuroimaging. A series of 419 children, aged from five months to 15 years, with epilepsy (medically refractory in 85.5% of them) associated with focal cortical lesions, who underwent surgery between 1986 and 2006 was analyzed to identify the factors that correlated with outcome. Mean follow-up was 5.2 years. According to Engel's classification; 75.8% of the children were seizure-free. When the lesion was well defined, correlations between clinical data, radiological features and electrophysiological features, suggesting a zone of seizure onset around (or even in) the lesion, was the best guarantee of achieving good seizure control by lesionectomy. Nevertheless, seizure outcome was also determined by other factors: the duration of the epilepsy and the surgery. Persistence of seizures was found to be significantly associated with the preoperative duration of epilepsy, the completeness of the lesional resection and de novo brain damage induced by the surgical procedure itself. Early surgery must be considered in children because of the benefits of seizure control on the developing brain and the risk of secondary epileptogenesis.