We report the case of a 29-year-old patient, who suffered from drug resistant laughing seizures since childhood. The clinical examination was normal, except for sequelae of hand and feet surgery during infancy for post-axial polydactyly. Cerebral MRI showed a hypothalamic hamartoma. The association of complex limb abnormalities with hypothalamic hamartoma lead to the diagnosis of Pallister-Hall syndrome. This syndrome is related to a mutation of gene GLI3, located on chromosome 7p13, and its inheritance is autosomal dominant. In the case of laughing seizures, a cerebral MRI should be performed to look for a hypothalamic hamartoma. The observation of such lesions indicates the necessity of standard radiographies of the hands and feet, to search for associated abnormalities. These findings might help to recognize a Pallister-Hall syndrome, thus allowing genetic counseling.