We retrospectively reviewed our clinical experience with PGB when used as add-on therapy in 101 patients (56 women and 45 men) with refractory partial epilepsy, who have been followed up for at least 1 year. Mean age was 40 years (16-64); mean number of concomitant AEDs was 2.8. Most patients (43) had temporal lobe epilepsy. Median number of seizures per month was 16 (3-240). Mean PGB dose used was 412.5 mg. Responder rate (percentage of patients with >or=50% seizure reduction) at 6 and 12 months was 52% and 39.6%, respectively. Seizure freedom for at least 6 and 12 months has been achieved by 12 patients (11.8%) and 6 patients (5.9%) respectively. At 1 year, 61 patients (60.4%) are still taking PGB. Forty patients have discontinued PGB, because of inefficacy (16 patients, 15.8%), adverse effects (15 patients, 14.8%) or both (9 patients, 8.9%). Sixty per cent of patients reported adverse events, being weight gain (>10% body weight) the most frequent, seen in 26 patients (25.7%). Dizziness/ataxia was seen in 20 (19.8%). Adverse effects were generally mild to moderate.