In the four decades since its discovery nuclear magnetic resonance (NMR) has become an indispensable tool for obtaining chemical information often. inaccessible by other methods. With the development of instruments of increasingly higher magnetic field strengths, the integration of powerful computers and the availability of an expanding array of flexible software new applications and developments have proliferated rapidly. Among the more exciting new advances is the use of NMR spectroscopy to probe biological systems. The last ten years have witnessed tremendous progress in the development of new NMR imaging and spectroscopic techniques for research and diagnostic applications. The ability to investigate metabolic processes and anatomical structure of intact biological systems under conditions that are totally non-destructive and non-invasive clearly provides much of the impetus for the intense activity that has been generated in the fields of medicine, radiology and the allied basic sciences. Significant advances have been made in this brief period: Whole-body proton NMR imaging today provides anatomical definition of normal and abnormal tissue with a contrast and detection sensitivity often superior to those of X-ray computed tomography and other competing imaging methods. Biochemical pathways, using NMR spectroscopy of protons, carbon-13 and phosphorus-31 nuclei in live animals and man can readily be followed by surface-coil methods to detect metabolites in localized regions. Indicative of the importance and widespread acceptance of these techniques is the explosive growth that the NMR literature is experiencing. This augers well for the future.