To assess the association between clinical and MRI characteristics of arterial ischaemic stroke (AIS) and the 3-year risk of post-stroke epilepsy (PSE) in paediatric patients. Retrospective cohort study. Database from a single tertiary referral centre for paediatric stroke in Chile. Two hundred seven neonates and children (1 day to 18 years) with a first-ever supratentorial AIS diagnosed between January 2003 and December 2019 were evaluated. Diagnosis of PSE and explanatory variables were consecutively recorded from hospital inpatient and annual outpatient records in a predesigned database. Competing risk analysis (competing events: death and loss to follow-up) of multiple Cox proportional hazards regression was performed to estimate adjusted subhazard ratios (SHRs) of PSE. Confidence intervals (95% CI) were calculated using bootstrap resampling (1000 replications). Interaction terms were added to investigate moderating effects. The 3-year incidence rate of PSE was 166.5 per 1000 person-years (neonatal: 150.1; childhood: 173.9). The 3-year cumulative incidence was 33%. Patients with acute symptomatic non-status seizures (SHR = 3.13; 95% CI = 1.43-6.82), status epilepticus (SHR = 5.16; 95% CI = 1.90-13.96), abnormal discharge neurological status (SHR = 2.52; 95% CI = 1.12-5.63), cortical lesions (SHR = 2.93; 95% CI = 1.48-5.81), and multifocal infarcts with stroke size < 5% of supratentorial brain volume (SHR = 3.49; 95% CI = 1.44-8.46) had a higher risk of PSE.Conclusion: This study identified specific and reliable acute clinical and imaging predictors of PSE in paediatric patients, helping clinicians identify high-risk patients with potential implications for treatment decisions.