PURPOSE: To evaluate the MR imaging findings of chondrosarcomas by correlation with pathologic classificationand grade. MATERIALS AND METHODS: We performed MR imaging-pathologic correlation of nineteen chondrosarcomas. Conventional chondrosarcomas accounted for 15 cases (grade I : 6, II : 6, III : 3) and the mesenchymal and dedifferentiated types each accounted for two. MR signal intensity (SI) of the tumor on T1- and T2-weighted images(T1WI and T2WI, respectively), was classified as homogeneous or heterogeneous low-, iso- or high SI, and enhancing pattern as marginal, marginal and septal, marginal and nodular, or diffuse enhancement. RESULTS: Eighteen cases of chondrosarcomas (95%) showed homogeneous or heterogeneous low- or iso SI on T1WI and high SI on T2WI. Low gradeconventional chondrosarcomas showed marginal and septal (n=8/10) or marginal (n=2/10) enhancement on Gd-enhanced MR images. Grade III conventional chondrosarcomas showed marginal or marginal and nodular enhancement. Dedifferentiated and mesenchymal chondrosarcomas showed marginal and nodular or diffuse enhancement. CONCLUSION: Chondrosarcomas showed iso- or low SI on T1WI and high SI on T2WI. Marginal and septal enhancement was demonstrated on Gd-enhanced MR images of grade I and II conventional chondrosarcomas. If a tumor showed amarginal and nodular or diffuse enhancing pattern, this suggested it was a of high grade chondrosarcoma.