Within the past decade in vivo NMR spectroscopy evolved from studies of cell suspensions and perfused tissues to investigations of intact animals and humans using large-bore magnets. In particular, phosphorus NMR based on the application ofsurface coils has been demonstrated to provide new insights into the energy metabolism in vivo and its diseased states. More recently, more sophisticated techniques have been described that may be used for full localization of a volume of interest (VOI) deep inside the body independent of the sensitive region of a surface coil. In fact, gradientlocalized spectroscopy takes advantage of spatially selective excitation, i.e., tailored RF pulses in the presence of a magnetic field gradient, in the same way as slice selection is performed in NMR imaging. Although appropriate sequences turn out to be particularly attractive because of their high flexibility, care should be taken to avoid problems such as chemical-shift artifacts in the definition of the VOI and potential signal losses in the presence of fluid flow or movement of the sample. Chemical-shift artifacts must be overcome by using strong slice-selection gradients and relatively broad RF pulses. Unfortunately, these conditions cause an even more pronounced loss of signal due to inadequate rephasing of spins moving along the gradient directions. Moreover, for long echo times as commonly employed for proton NMR spectroscopy using the 90”-90”-90” stimulatedecho (I) or 90”-180”180” double-spin-echo (2) localization method, the sensitivity to motion might include rather small velocities. The aim of this communication is to describe motion-induced signal losses under typical experimental conditions, as, for example, encountered for proton spectroscopy of the brain in vivo, and to demonstrate the successful adaptation of motion-compensating gradient waveforms recently proposed for NMR imaging techniques (3). In our particular localization method (I), three slice-selective 90” RF pulses are applied in succession, using orthogonal magnetic field gradients. Spectra are recorded from the stimulated echo arising from material at the intersection of the three excited planes. In addition to the stimulated echo, the third RF pulse generates an unwanted free induction decay which must be dephased by a further gradient. It might therefore be advantageous to rephase each slice-selection gradient of the STEAM sequence only after the third pulse to maximize the dephasing effect imposed onto the unwanted FID. However, it is this approach that makes the stimulated echo particularly sensitive to motion, resulting in a loss of signal from moving spins. An alternative sequence