In vivo Magnetic Resonance Spectroscopy (MRS) allows the non-invasive detection and quantification of a number of metabolites from localized volumes within a living organism. MRS localization techniques can be divided into two main groups, single voxel and multi-voxel. Single voxel techniques provide the metabolic profile from a specific small volume, whereas multi-voxel techniques are used to obtain the spatial distribution of metabolites throughout a large volume subdivided into small contiguous voxels. This chapter describes standard protocols for the acquisition and processing of in vivo single voxelH MRS data from the rodent brain.