Background and purpose: After first-ever ischaemic stroke, to assess the risk and baseline factors associated with acute symptomatic seizure (ASS) (occurring within 7 days) and late post-stroke seizure (LPS) (>7 days). Methods: All consecutive patients aged 15-49 with first-ever ischaemic stroke between 1994 and 2007 treated at the Helsinki University Central Hospital were included, using Cox proportional hazard models to identify factors associated with seizures. Adjustment was for age, gender, vascular risk factors, admission hyperglycemia (>6.1 mm) and hyponatremia (<137 mm), use of psychiatric medication, stroke severity (NIH Stroke Scale) and anatomical (Bamford criteria) and etiological (Trial of Org in Acute Stroke Treatment) stroke subtype. Results: ASSs emerged in 35 (3.5%) patients. LPSs (n = 102) occurred at a cumulative rate of 6.1% at 1 year, 9.5% at 5 years and 11.5% at 10 years. In multivariate analysis, anxiolytic use at time of index stroke (hazard ratio 13.43, 95% confidence interval 3.91-46.14), moderate stroke severity (3.95, 1.86-8.41), cortical involvement (3.69, 1.66-8.18) and hyponatremia (3.26, 1.41-7.57) were independently associated with ASSs. Risk factors for LPSs were total anterior circulation infarct (15.94, 7.62-33.33), partial anterior circulation infarct (3.48, 1.52-7.93), history of ASS (3.94, 2.07-7.48), antidepressant use at the time of LPS (3.88, 2.46-6.11), hemorrhagic infarct (1.94, 1.19-3.15), male gender (1.79, 1.10-2.92) and hyperglycemia (1.62, 1.05-2.51). Conclusions: In young ischaemic stroke patients, the magnitude of seizure risk and the major risk factors were similar to older ischaemic stroke patients but risk factors for ASSs and LPSs differed.