PURPOSE: Central neurocytoma is a reae neuronal differentiated intraventricular tumor of young adults. The purpose of this study was to evaluate the characteristic MR appearance of central neurocytoma. MATERIALS AND METHODS: We retrospectively reviewed MR images of 12 patients with central neurocytoma, confirmed by ultrastructural and immunohistochemical study. We analyzed patient age, and on all sequences, tumor location,extension into the third ventricle, involvement of brain parenchyme, cyst, hemorrhage, vascular signal void and signal intensity ; and egree of Gd-enhancement was examined on MR images, pattern of calcification on CT, and neovascularity, tumor staining on angiography. RESULTS: Age distribution was wide ranging from 26 to 64 years; the most frequent was age group was the forth decade (five patients). All tumors except one (in the third ventricle) were located in the lateral ventricle and most were seen in the region of the foramen of Monro (10 cases). Tumors showed extension into the third ventricle and involvement of parenchyma in three cases. The internal architecture of the tumor was heterogenous and consisted of cysts(83%), hemorrhage(25%) and vascular signal void(25%). The solid portion of the tumor showed variable signal intensity on T1-weighted images and iso or high signal intensity on T2- and proton density-weighted images. On MR imaging, mild to moderate heterogenous Gd-enhancement was seen in ten cases(83%), and on CT, a spotted, amorphous, nodular pattern of calcifications was seen in seven cases(63%). On angiography, neovasevlarity and tumor staining was seen in three cases(100%). CONCLUSION: The typical location of the lateral and third ventricles and MR imaging characteristics including variable signal intensity and heterogenous internal architecture are helpful in the diagnosis of central neurocytoma in young adults.