Pooled data analysis was performed on individual data from 807 pregabalin- and 367 placebo-treated patients with treatment-resistant partial seizures with or without generalization from four placebo-controlled studies evaluating the short-term efficacy, safety and tolerability of add-on pregabalin 150-600 mg/day. Short-term add-on treatment with pregabalin resulted in statistically significant reductions from baseline in seizure frequency and statistically significantly higher responder rates over placebo (OR 5.93 [95% CI 4.10, 8.57]). Its overall tolerability was good, with an OR of withdrawing from the study due to any reason of 1.71 (95% CIs 1.24, 2.35). The most commonly reported AEs were dizziness and somnolence, however, they were most pronounced during the first week of treatment, followed by a sharp fall in incidences across all dosing groups to <5% from Week 2 and onwards. Weight gain, reported by 5.4-17.1% of patients across pregabalin dosing groups, appeared to be dose-related, but it led to study withdrawal in only 0.74% (6 out of 810) pregabalin-treated subjects. Our analysis suggests that pregabalin has a robust efficacy and good tolerability demonstrated in a study population more treatment-refractory compared to the one enrolled into short-term studies of other new antiepileptic drugs.