Coagulase-negative staphylococci (CoNS), originally described as ubiquitous commensals of the healthy human skin and mucosa, have emerged as important opportunistic pathogens primarily causing healthcare-associated infections in patients with indwelling medical devices. Recent studies, utilizing new molecular typing methods, particularly on Staphylococcus epidermidis, have increased our understanding of the mechanisms that contribute to the evolutionary success of these extremely versatile microorganisms. In the following mini-review, we summarize recent research in this area focusing on the molecular methods and epidemiology of S. epidermidis and S. saprophyticus.