Nosocomial infections are responsible for a very high level of morbidity and mortality in healthcare establishments. According to various studies carried out in hospitals in developed countries, 5 to 10% of hospitalised patients acquire a nosocomial infection. According to the various surveys of the prevalence of nosocomial infection carried out in Algeria across the different hospitals. The instantaneous prevalence varied between 3.9% and 15.2%. Among the situations that can be blamed for the transmission of nosocomial infections, the most important are: inadequate hand washing and disinfection; care practices that are not rigorous; environmental contamination (air, water, etc.); poor work organisation; therapeutic pressure (antibiotics, corticosteroids, etc.); failure to comply with protocols and procedures. This manual provides a simple explanation of the rules of hygiene for care staff in health care establishments. It could also be used as a teaching and learning tool for health care providers in different health care establishments.