Lipoteichoic acids (LTAs), glycolipids and, less wide-spread, teichoic acids (TAs) are characteristic components of the cell wall-membrane complex in a large group of gram-positive bacteria (for references see [17, 18]). After a period of hypotheses for essential functions [46], LTA and TA were for a while considered as more or less secondary cellular components, but this view is now changing again. There is clear evidence that TA is indispensable for the viability of Bacillus subtilis [50]. In Staphylococcus aureus, TA is needed for normal growth [10] and becomes indispensable for growth under extreme conditions (W. Fischer, unpublished data). Notably, no mutants lacking LTA have yet been detected on chemical mutagenesis, either in S. aureus (W. Fischer and K. Leopold, unpublished data) or in Lactobacillus casei [51]. For these reasons the biosynthetic pathways of TA and LTA have gained interest as possible targets for new antibiotics. This brief overview is focussed on LTA, TA and membrane lipids of S. aureus but biosynthetic and functional aspects of these components are similar in other gram-positive bacteria [17, 18].