OBJECTIVES: The aim of this study was to understand the current impact of partial onset seizures (POS) on health outcomes and costs. METHODS: Patients were identified from the 2010 & 2013 5EU and 2011-2012 Brazil National Health and Wellness Survey, a nationally represented, internet-based survey of adults (18+ years). Patients self-reported a diagnosis of epilepsy with POS and were categorized into ≥1 seizure per week, 1-3 seizures per month, 1-4 seizures per year, <1 seizure per year (reference). Patients completed the SF-36v2 (mental (MCS), physical component summary (PCS)), SF-6D (health utility), Work Productivity and Activity Impairment Questionnaire and reported on resource utilization in the past six months. Costs were estimated from the literature. Generalized linear regression analyses were conducted controlling for covariates (e.g., age, gender, marital status, comorbidities, years diagnosed with epilepsy). RESULTS: There were 175 patients in the 5EU and 32 in Brazil,11.1% reported ≥1 seizures/week, 7.7% reported 1-3 seizures/month, 26.1% 1-4 seizures/year, and 55.1% <1seizures/year. MCS, PCS, utilities, productivity loss and resource were similar in Brazil and the 5EU (all p>0.05). After adjustments (combined 5EU and Brazil), as the number of seizures decreased, PCS (≥1 seizures/week: 40.9; 1-3 seizures/month: 41.7; 1-4 seizures/year: 46.9; <1seizures/year: 48.4) and health utilities (≥1 seizures/week: 0.58; 1-3 seizures/month: 0.63; 1-4 seizures/year: 0.63; <1seizures/year: 0.69) increased. As the number of seizures decreased, activity impairment (≥1 seizures/week: 58.6%; 1-3 seizures/month: 51.1%; 1-4 seizures/year: 35.7%; <1seizures/year: 25.5%), emergency room visits and hospitalizations decreased. In Europe direct and indirect costs were highest for the ≥1 seizure/week group. CONCLUSIONS: POS burden was similar in Europe and Brazil. As the number of seizures increased, economic and humanistic burden increased. Even with the large number of treatment options available, patients and the healthcare system need additional choices to reduce the frequency of seizures.