State-of-the-art methods for in vivo localized NMR spectroscopy are described. The methods are presented according to the type of pulse sequences implemented and the number of spatial dimensions which are obtained. The advantages and limitations of methods based either on (i) surface coil, (ii) complex radiofrequency pulse sequences with or without gradients, or (iii) double phase encoding (spectroscopic imaging) are discussed. The specific features of 31P and 1H localized spectroscopy are presented with a description of potential clinical applications of this approach which affords precise biochemical and metabolic information on a variety of organs and tissues in a strictly non-invasive manner.