We developed a junior-real-time neuropsychological testing (j-RTNT) and used it during surgery of a right fronto-insular dysembryoplastic neuroepithelial tumor causing seizures in a 16 years old female. The j-RTNT included tasks from the battery NEPSY-II. Pre-surgery evaluation detected a below average performance in visuo-spatial planning, inhibition, visual attention, planning and borderline performance in speeded naming. The j-RTNT allows detecting sudden decreases that could be caused by resection. During surgery, ECoG was characterized by slow sharp activity and spikes on the electrodes exploring the right fronto-polar region. After the resection, spikes were not detected anymore. Immediate post-surgery performance resulted within the normal range, remained below average in visuo-spatial planning, and improved in inhibition, switching and in speeded naming. Follow-up revealed cognitive recovery. Neurological assessment was unremarkable and the patient was seizure free. No epileptic activity could be observed on follow-up EEG. fMRI data showed that in the follow-up vs. pre-surgery there was a higher recruitment of the right superior frontal gyrus, a region involved in the cognitive execution and cognitive control networks. The j-RTNT is feasible with young patients, goes beyond the testing of limited functions, assessing multiple times during resection several different functions to better monitoring the effects of resection.