PURPOSE: To evaluate the significance of fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) images for the diagnosis of intracranial tumors. MATERIALS AND METHODS: MR imaging was used to study15 patients with various intracranial tumors and were compared the findings according to fast spin echo and fast FLAIR images. RESULTS: In 12 of 15 patients, tumor signal intensities on FLAIR images were consistent with those shown on T2-weighted (T2W) images. In seven of eight patients who had cystic or necrotic components within the mass, FLAIR images showed isosignal intensity and in the other patient, high signal intensity was seen. There was variation in the signal intensity from cerebrospinal fluid (CSF). In 12 of 13 patients in whom edema was associated with tumor, FLAIR images were clearer than T2W images as their signal intensity was brighter. In eight patients, however, FLAIR and T2W images provided a similar definition of the margin between edema and tumor. In six patients with intratumoral hemorrhage, FLAIR and T2W images showed the same signal intensities at all stages of the hemorrhage except the chronic cystic stage. CONCLUSION: We concluded that in the diagnosis of intracranial tumors, FLAIR images can supplement conventional spin-echo images.