OBJECTIVE: To study clinical and imaging features of hypothalamic hamartoma in children. METHODS: Imaging findings and clinical manifestations of 38 children with hypothalamic hamartomas were retrospectively reviewed. The patients included 25 boys and 13 girls, ranging in age of onset from 1 month to 15 years. All the 38 patients were examined with pre-contrast and post-contrast T1 weighted MR imaging and with non-contrast T2 weighted MR imaging. Meanwhile, 10 patients received CT scan. Hypothalamic hamartomas were confimed by pathologic examinations in the 38 patients. RESULTS: Gelastic epilepsy, precocious puberty, other types of epilepsy and disturbance of intelligence were main manifestations in the 38 patients. Gelastic epilepsy was found as an initial clinical symptom in 17 cases, precocious puberty in 13 cases and other types of epilepsy in 8 cases. All masses were located in the suprasellar and interpeduncular cistern. They showed iso-density on CT scan, and homogeneous signal iso-intense to gray matter on T1 and T2 weighted MR images. With contrast MR images, there was no enhancement in the mass. The size or pedunculation of the mass was not correlated with clinical features. CONCLUSIONS: Hypothalamic hamartoma may be characterized by precocious puberty and/or gelastic epilepsy and specific imaging findings mentioned above.［Chin J Contemp Pediatr, 2009, 11 (5):364-366］