Metabolomics deals with a comprehensive evaluation of metabolites, which reflect all functional activities, transient effects, and also endpoints of processes in biological systems. Metabolomics provides a snapshot of the physiological state, which is determined by the sum of its genetic composition, regulation of gene expression, protein function, and environmental influence. Successful metabolomic analyses rely on proper experimental design, standardized sample processing, versatile analytical methods, and large scale bioinformatics. This chapter provides an overview on practical aspects of metabolomics including aims, experimental design, as well as methods for sample processing and analytics. It will introduce the reader to the analytical tools like gas and liquid chromatography coupled to mass spectrometry. Moreover, different types of metabolomics such as profiling, non-targeted and targeted metabolomics, which contribute to versatile analyses of the metabolism, will also be discussed. Additionally, details will be provided on the application of metabolomics in human and animal studies.