Gelastic (laughing) epilepsy is characterized by recurrent unprovoked episodes of stereotyped, brief and mirthless laughter. Hypothalamic hamartoma is most often the cause of gelastic epilepsy. Hypothalamic gelastic epilepsy presenting as a progressive epileptic disease is well known, but isolated without multiple seizure types, precocious puberty, cognitive decline and behavioural problems is not usually reported. We report a case of refractory gelastic seizures associated with indolent hypothalamic hamartoma and polysyndactyly with a follow-up of 18 years. Our case highlights the possibility of underdiagnosed hypothalamic hamartomas and unrecognised gelastic epilepsy in paediatric population.