OBJECTIVES: To evaluate the burden of 30-day readmissions in adjunctively-treated patients with epilepsy. METHODS: The MarketScan^®retrospective database (Jan-2006 to Dec-2011) was used. Selected patients had: ≥1 diagnosis code for epilepsy (ICD-9 345.xx), age ≥18, ≥1 hospitalization (index), and received adjunctive AEDs during study period. Eligible patients had 60 days pre- and ≥365 days post-index continuous enrolment. Patients were stratified by type of hospitalization (all-cause or epilepsy-related) and by partial vs. generalized epilepsy diagnosis. Readmissions were defined as any hospitalization occurring <30 days from the preceding hospitalization’s discharge date. RESULTS: Of a total of 504,507 patients, 141,017 (19%; age 51±17.6; 59% female, average follow-up 1,188 days) had ≥1 all-cause hospitalizations, and of these, 91,587 (65%) had an epilepsy-related admission, and 41,453 (29%) had ≥1 all-cause 30-day readmissions.  Forty-six percent of patients (8,955) had epilepsy-related readmissions. Among patients with epilepsy-related hospitalizations, 19,115 (21%) had ≥1 all-cause 30-day readmissions, 61% of whom (11,670) had epilepsy-related readmissions. Partial epilepsy accounted for 9,882 (7%) of the total number of patients hospitalized (all-cause) during the study period; 100% of these patients had one or more epilepsy-related admissions. Among the hospitalized (all-cause) with POS, 1,729 (18%) had ≥1 all-cause readmissions, and of these 1,140 (66%) had ≥1 epilepsy-related readmissions. Among POS patients with epilepsy-related hospitalizations, 1,502 (15%) had ≥1 all-cause readmissions, and of these 1,055 (70%) had ≥1 epilepsy-related readmissions.  CONCLUSIONS: In this study, approximately one in three patients with epilepsy hospitalized for any reason had a 30-day readmission, with approximately half of these patients presenting 30-day readmissions due to epilepsy. Approximately 60% of patients with an epilepsy-related admission had a 30-day readmission due to epilepsy. Patients with partial epilepsy had a greater burden of epilepsy-related hospitalizations and readmissions.