ObjectiveTo assess seizure semiology and disease evolution in a large number of hypothalamic hamartoma (HH) patients.MethodsSeizure semiology and associated medical records for 78 patients with HH‐related epilepsy were retrospectively reviewed. Potential predictors of seizure types were assessed through univariate and binary logistic regression analyses.Results57 (73.1%) patients presented with gelastic seizures at the onset of epilepsy, of whole 39 (68.4%) experienced additional seizure types with a mean latency interval of 4.59 years. Automatism, version, and sGTCs were increasingly common with disease evolution. The intraventricular size of HH was significantly negatively correlated with the disease evolution interval (r = −0.445, p = 0.009). A significantly higher rate of patients with automatism in the DF‐II group relative to the DF‐III group was found in both χ2 (X = 6.07, p = 0.014) and logistic regression analyses (B = 3.196, p = 0.020).InterpretationGelastic seizures are the most common initial seizure type in HH patients, but variable semiologies occur with disease evolution. The intraventricular HH lesion size is an important determinant of epilepsy evolution. DF‐II HH lesions contribute to a higher chance of automatism evolution. The present study furthers our understanding of the dynamic organization of the seizure network affected by HH.