Hospital infections. Modern medicine, besides of all the wonderful achievements, brings about some negative consequences in the form of higher susceptibility to infections, especially in the hospital environment. Hospital infections exist as long as organized patient care. Despite the tremendous advances of today's medicine they are a big threat to the patient and medical personnel on national as well as international level. Studies performed in developed countries have shown that the incidence of hospital infections ranges from 5 to 10%. Introduction of ever growing number of surgical procedures, high invasiveness of diagnostic methods and the use of medical equipment that is difficult to sterilize is continuously increasing the risk of infections. They are also a definite adverse result of broad antibiotic use and growing antimicrobial resistance. It is therefore vital to work on their control and preventive methods by making use of strict surveillance of hospital infections. Currently, there is growing recognition of this problem and the need for performing continuous epidemiologic surveillance with the aim to lower the incidence of hospital infections and to combat the negative outcomes they may have on health and economy.