In diffusion-weighted magnetic resonance imaging (DWI-MRI), the observed MRI signal intensity is attenuated by the self-diffusion of water molecules. DWI can provide information about the microscopic structure and organization of biological tissue and thus can depict various pathological changes of organs or tissues. DWI has been successfully used for the characterization of bone marrow alterations or lesions, and in particular for the differentiation of benign and malignant vertebral compression fractures. In this review article, the basics of DWI are introduced, and several pulse sequences that have been used for DWI of the bone marrow are described. Subsequently, an extensive overview about diffusion studies of the bone marrow and in particular of DWI of vertebral compression fractures is provided.