Objective. Symptomatic focal epilepsy is frequently caused by supratentorial brain tumors that may be surgically removed. The authors studied outcomes of surgical treatment depending on the use of electrocorticography c (ECoG). Material and methods. Seventy-five children, aged 5—7 years, with supratentorial brain tumors were examined. Symptomatic epilepsy was found in 52 (69.3%) patients. Dysembryoplastic neuroepithelial tumors (DNET) and fibrillary astrocytomas were the most epileptogenic tumors. Results and conclusion. The outcomes on the Engel scale were as follows: in 27 patients with surgical intervention without ECoG: class I — 9 patients, class II — 7 patients, class III — 5 patients, class IV — 6 patients and in 25 patients operated with ECoG: class I — 19 patients, class II — 4 patients and class III — 2 patients. The significant difference (p<0.01) between I+II Engel classes in comparison with III+IV Engel classes in operated patients demonstrated the necessity of ECoG during surgery in the resection of supratentorial brain tumors in patients with symptomatic epilepsy.