It is commonly believed that sulci offer a natural path to reach deep-seated lesions. However, it has also been argued that this approach carries a risk of damaging the vessels during the opening of the sulcus. We therefore were prompted to test the possibility of finding a transcortical path identified as non-functional by intraoperative brain mapping. A successful resection is presented of a left posterior isthmus clear cell ependymoma through a selected corridor based on functional mapping in an awake patient. MRI performed at 12 months showed no tumour recurrence. Pre- and postoperative extensive testing confirmed an improvement of the patient's cognitive functions. Therefore, we were able to demonstrate the feasibility of a functionally tailored transcortical approach as an alternative to the transulcal approach for deep-seated lesions. This concept should be validated in a larger patient series.