PURPOSE: To determine differential points, if any, on MR imaging between cerebellar cystic hemangioblastoma and cystic astrocytoma. MATERIALS AND METHODS: MR images of patients with surgically proven cerebellar cystic hemangioblastomas (n=12) and cystic astrocytomas (n=14) were retrospectively reviewed with regard to the following points: size, location and signal intensity of the tumor ; tumor margin; presence, size and location of the enhancing mural nodule; vascular signal voids, internal septations, enhancing feature of the cyst wall, secondary findings (degree of peritumoral edema and presence of hydrocephalus) and the patient's age. RESULTS: The significant (p<0.5) differential points were vascular signal voids, which were the most important clue, as well asthe presence of an enhancing mural nodule, tumor margin, enhancing feature of the cyst wall and the patient's age.If the patient was an adult and presented an enhancing mural nodule with adjacent vascular signal voids and smooth tumor margin, then cystic hemangioblastoma was suggested, While the presence of an irregular-margined thick enhancing cyst wall, mural nodule without adjacent vascular signal voids and pediatric age were suggestive of cystic astrocytoma. CONCLUSION: On MR imaging, there are certain significant differential points between these similar-appearing tumors and these would be useful for a more accurate diagnosis.