Among the greatest achievements of medicine in recent decades belong to the significant decrease of morbidity and the pestilence of the various diseases that have been fatal. The increased standard of living, the discovery of the drugs and generally better health care has enabled the early detection and treatment of patients. The purpose of this paper is to get acquainted with the most common bacterial diseases that attack children as well as know the ways of prevention. It is also the purpose of explaining the role of teachers in the prevention and illness process. Vaccination (active immunization) is the most effective and economically the most efficient way to protect individuals and the population of the infectious diseases. In Croatia, as well as in other more developed countries of the world, organized vaccination of children is implemented from the middle of last century. Because of that some infectious diseases are almost or completely suppressed (diphtheria, tetanus, typhus abdominalis) while some other diseases are drastically reduced (whooping cough, tuberculosis). Public health impact of vaccination in removing a specific disease is expected if it is in the community reached a high degree of vaccine coverage (90 to 95% children). Many bacterial diseases begin with the same or similar clinical symptoms making it difficult to establish accurate diagnosis. This work describes in detail the course of each disease, treatment and prevention. Socio-economic conditions, genetic characteristics, the age of the child, and the level of health care significantly affect on how serious the consequences will be. It is important to emphasize the role of a teacher who spend a lot of time with pupils during the day. Their importance is in trying to identify symptoms and respond quickly for the purpose of informing parents and medical service. Another teacher roles are to empower pupils for independent and individual care of personal hygiene and health and to awake them to the importance of preventing and preventing the spread of infectious diseases.