NMR spectroscopy of serum or plasma represents a highly efficient way to gain information on the distribution and composition of lipoproteins, while simultaneously estimating levels of highly abundant small molecules in blood. The approach allows the user to access information on systemic metabolism, diet and other exposures, and core physiological processes including specific information about organ function and pathology. Subsequently, 1H NMR spectroscopy of serum and plasma became a major component of the developing field of metabonomics/metabolomics, while in parallel becoming a genuinely new clinical chemistry platform. It has been used extensively to predict, detect and monitor cardiometabolic disease and to elucidate the causal relationships between blood molecules and chronic disease risk. Today, the application of NMR analysis of blood serum/plasma is at an important crossroads, with the expansion of national centres of excellence and commercially available platforms and with large-scale human studies becoming more commonplace. This makes NMR-based metabolomics in principle a widely accessible clinical tool open to many researchers or even the private individual for health assessment. Herein is described the experimental methodology and progress to-date of this growing success story for biological NMR spectroscopy.