Despite all improvements in medicine, infectious diseases have always been one of the major health problems in the world. The control of infectious diseases by vaccines is the most effective, safe and cost-effective means of coping with these diseases. Although there are lots of vaccines in use, social and economic conditions and status of the countries and the incidence of certain infectious diseases lead countries to establish their own vaccine schedules. This article, aimes to explain the basic principles of immunization for family medicine specialists, general practitioners and pediatricians, whose first duty is to give preventive care services.