The long-term prognosis of pharmacological therapy in patients with mesial temporal sclerosis (MTS) is generally considered poor. On the contrary, successful surgical therapy is frequently reported. We performed a retrospective case record survey of patients with MTS in a comprehensive epilepsy center between 1993 and 1999 in order to develop treatment strategies. The time period allowed access to high-resolution qualitative magnetic resonance imaging (MRI) and a minimum of 1-year outcome assessment. Eighty-three patients with intractable partial epilepsy with MRI and electroencephalograph (EEG) abnormalities and seizure semiology consistent with temporal lobe epilepsy were identified. Thirty-six patients were treated pharmacologically and surgically and 47 patients received only pharmacotherapy. The number of patients who became seizure free was in total 37 (45%); in the surgical group 26 and in the non-surgical group 11. The proportions of seizure-free patients in each group were 72% (surgical) and 23% (non-surgical). Clinical factors such as age, gender, lesion side, previous medical history, duration of illness, seizure frequency and IQ did not correlate to prognosis. A good seizure outcome was associated with early age of seizure onset, low number of previously used antiepileptic drugs (AEDs) and surgical treatment. There is a better long-term outcome in patients with MTS receiving surgical therapy in comparison with medical therapy.