Objective To analyze the clinical and imaging features of subependymal giant cell astrocytomas in patients with tuberous sclerosis.Methods The clinical data of 48 patients with tuberous sclerosis,admitted to our hospital from July 2007 to August 2009,were collected.According to the patients' history,sign and MRI results,the clinical features and imaging characteristics of subependymal giant cell astrocytomas were analyzed.Results Four patients with tuberous sclerosis were diagnosed as having subependymal giant cell astrocytomas and 2 of them were also diagnosed as having obstructive hydrocephalus;these 4 patients were male with an average onset age of five years (ranged from 1 to 12 years old).Seizure and skin lesions were found in these 4 patients with 3 presenting cognitive dysfunction.CT scanning showed iso-density or slightly low density in subependymal giant cell astrocytornas and some of these tumors were calcified with high density.MRI showed TIWI iso-signal or low signal and T2WI iso-signai or high signal; FLAIR high signal was presented and asymmetrical signal was also shown when calcification happened;enhanced MRI showed significant intensification on the tumors.Conclusion Some patients with tuberous sclerosis can have subependymal giant cell astrocytomas,the slow-growing tumors,which are often adjacent to the foramen of Monro and lead to obstructive hydrocephalus.Long-term follow-up needs to be conducted to find tumors at an early stage in patients with tuberous sclerosis.