In most patients with acute leukemia very low or absent lipid signals from central red bone marrow are detected using magnetic resonance (MR) techniques, in contrast to healthy persons with considerable signals from both, water and lipid protons. The proliferation of the malignant leukemic cells causes the displacement of fat cells in the marrow. This disorder is reversible during successful cytotoxic chemotherapy of acute leukemia: Lipid signals from vertebral bodies arise again due to the replacement of hypercellular leukemic marrow by fat. Different approaches for lipid selective MR imaging and spectroscopy are reported and results from typical examples are demonstrated and discussed. The report is based on examinations of 12 patients with leukemia in follow-up studies, 11 patients with other disorders of bone marrow, and 26 healthy volunteers.