In the present study, the protein profiles of the cell wall (CW) extracts of eight Staphylococcus epidermidis strains were analysed. The protein pattern of the extracellular matrix (EM) of four S. epidermidis good biofilm producer strains was also obtained. The main goal was to relate these protein patterns with their bacterial adhesion and biofilm forming ability. For this purpose, 2 h adhesion and 8 d-old biofilm assays were carried out, with the adhered cells and biomass quantified by microscopic observation and crystal violet quantification, respectively. CW and EM proteins were visualized by SDS-PAGE. According to the results, a significant percentage of the CW proteins detected was common to all the strains studied. However, the most adhering strains expressed a high number of proteins associated with the initial adhesion process, and the strongest biofilm producers expressed proteins that were absent in the protein profile of the strains that produced lower amounts of biofilm. Therefore, the present results demonstrate the importance of such proteins in adhesion and biofilm formation processes. Some of the CW proteins were also present in the EM protein pattern, though to a smaller amount, as well as several exoenzymes important for the host immune system invasiveness. (C) Koninklijke Brill NV, Leiden, 2009