This pilot study evaluated whether a type of non-invasive brain stimulation called slow-oscillatory transcranial direct current stimulation (so-tDCS) can reduce seizure frequency in patients with drug-resistant focal epilepsy. Ten patients received 14 days of so-tDCS (2 mA, 1 Hz) for 20 minutes twice daily, guided by their individual seizure focus identified by EEG and MRI. Seizure frequency and epileptiform discharges were measured before, during, and up to 8 weeks after treatment. The study also assessed safety and tolerability. Results showed that so-tDCS significantly reduced seizure frequency, with the greatest effect occurring during the first week of treatment, and the benefit was sustained during follow-up. No serious adverse events were reported. These preliminary findings suggest that so-tDCS may be a safe and effective non-invasive option for refractory focal epilepsy, but larger sham-controlled trials are needed to confirm efficacy.