The application of infrared spectroscopy to the physicochemical characterization of glycolipids as biologically important membrane constituents is described. In this contribution, the analysis of diacyl- and sphingosine-based (cerebroside, ganglioside) oligosaccharides and the class of lipid A-anchored lipooligo- and polysaccharides is reviewed. Furthermore, interaction of glycolipids with various agents as well as of sugars with membranes are discussed. The reviewed data prove the capacity of FTIR spectroscopy to monitor intra- and intermolecular interactions under physiologically relevant conditions refering to pH, temperature, and ion concentrations. This includes the characterization of acyl chain order and the betaalpha chain melting transition, cation and drug binding to charged groups, and supramolecular organization of the glycolipid aggregates. In various examples, the biological relevance of IR data analysis are presented.