MR imaging is an essential tool for the evaluation of musculoskeletal neoplasms in children. It provides useful information for diagnosis, determination of extent of disease, assessment of response to treatment, and detection of complications and effects of therapy. This article reviews the current role of MR imaging in each of these situations. A protocol for the evaluation of these lesions is suggested. Also addressed are issues related to differentiating pathologic conditions, normal marrow, and cartilaginous structures of the pediatric skeleton.