Different approaches were used to examine the function of teichoic acids (TA) as phage receptors among selected Listeria strains, and to identify and characterize specific receptor structures of host cells belonging to different serovars. This included successive removal of cell wall constituents, preparation and purification of TA, and GLC analysis of TA components. Adsorption of Listeria monocytogenes bacteriophages could be inhibited by polyvalent antisera, specific lectins and addition of purified TA. The results confirmed the necessity of TA in general and of rhamnose and glucosamine in particular for adsorption of Listeria phage A118, which is a temperate Siphovirus (morphotype B1), attacking predominantly serovars 1/2. Host binding of siphoviral phage A500 (predominantly lysing serovars 4b), was also dependent on cell wall TA. A phage-resistant L. monocytogenes strain was shown to lack glucosamine in its TA. These results support the view that TA substituents may play an important role not only in antigenicity of Listeria cells, but also in specificity of host recognition by two temperate Listeria phages. In contrast, the broad-host-range virulent phage A511 (Myovirus, morphotype A1) uses the listerial peptidoglycan as primary receptor. This corresponds well with the observation that A511 is capable of lysing the majority of L. monocytogenes strains.