Despite improvement of infection control measures during the last 20 years, incidence of health care associated infections (HAI) remains high. HAI, also known as nosocomial infections, are mainly due to susceptible bacteria. However, resistant bacteria are responsible for some of them. In Switzerland, methicillin resistant Staphylococcus aureus incidence is decreasing but enterobacteriaceae producing extended spectrum beta-lactamase are increasing. In addition, emerging resistance challenges such as vancomycin-resistant enterococci or carbapenemase-producing bacteria were observed occasionally during recent years. Physicians in charge of hospitalized patients should know and apply good practice measures to prevent HAI and reduce the emergence and spread of multidrug resistant bacteria.