Nuclear magnetic resonance (NMR) has become a valuable tool for the study of metabolism in a wide variety of biological systems. Its inherent advantages are that it is non-destructive and non-invasive. Observations can be carried out not only on extracts and media but also on whole cells and whole tissues under varying conditions and over varying times. The information gained gives considerable insight into cellular metabolism. There has been, to date, relatively little literature on the application o f NMR to the biochemistry of parasites, presumably reflecting the paucity of interfaces between parasitologists and NMR practitioners as well as the inherent difficulties in obtaining sufficient parasite material for NMR experiments. These difficulties are being overcome and William O'Sullivan, Michael Edwards and Raymond Norton believe that NMR has a great deal to offer those interested in parasite metabolism. In particular, it has the capacity to turn up the unexpected, on important factor as so many parasites appear to have developed their own variations on orthodox metabolic pathways.