This study was undertaken to explore the perceived impact of having a seizure (SZ) compared with having an adverse effect (AE). Patients (N=201) with partial-onset epilepsy taking two or more antiepileptic drugs (AEDs) rated their health state from 0 to100 based on their health today, hypothetical health if experiencing a SZ today, and hypothetical health if experiencing an AE today. Overall health status ratings (HLTH) declined as SZ frequency increased (P=0.01). Perceived decrements in HLTH with SZs were greatest for patients with the least frequent SZs (P=0.001) and the most recent SZs (P=0.004). Perceived decrements in HLTH with SZs compared with AEs (SZ-AE) differed across SZ recency groups (P<0.05 except for muscle incoordination and weakness). Patients with the more remote SZs were most concerned with SZ control; patients with more recent SZs were more sensitive to AED side effects. These data provide insight into the risk-benefit concerns of patients at equipoise when addressing the efficacy and AEs of AEDs.