Publisher Summary This chapter discusses factors that affect growth and survival of microbial pathogens in cheese. The pathogens, Salmonella enterica, listeria monocytogenes, Staphylococcus aureus and enteropathogenic E. coli (ETEC) pose the greatest risk to the safety of cheese. If active lactic acid starter cultures are used, Staph. aureus is considered to be a low-risk pathogen. However, in traditional cheeses where active starter cultures are not used, Staph. aureus may pose a significant risk for toxin production in cheese if numbers are sufficiently high. The factors that contribute to the safety of cheese with respect to pathogenic bacteria include milk quality, starter culture or native lactic acid bacterial growth during cheese making, pH, salt, control of aging conditions and chemical changes that occur in cheese during aging. Other technologies may provide opportunities to add additional barriers to the growth of bacterial pathogens. It is particularly important for the producers of raw milk cheeses to have a documented and systematic approach to ensure product safety.