Vaccination is a procedure through which human body’s resistance is achieved against the causes of the contagious diseases; and through which more lives have been saved versus any other medicine out there. Public health programs for mass vaccinations have caused a decrease in death from contagious diseases that can be cured by vaccination. All of the vaccinations in use in the Republic of Croatia have gone all the necessary clinical testings and are registered by the HALMED (Agency for medicine and medicinal products). In Croatia, a procedure of vaccination is regulated by the laws and regulations that are issued by the Ministry of Public Health. The vaccination programs differ on a country level; also highly depend on economical and social environment as well as epidemiological characteristics of the infective diseases within the population. A vaccination calendar represents an order and the type of vaccine depending on the age of the child. The Program of Required Vaccination in the Republic of Croatia includes required vaccination again various diseases, which include following; tetanus, polio, tuberculosis, measles, mumps, diphtheria, hepatitis B as well as the diseases caused by Haemophilus influenzae type B. Parent/guardian’s independent decision whether to vaccinate their children is not their constitutional right. It is required to vaccinate children by the law and the constitution; the Constitutional Court established by its decision rejecting the proposal to assess the constitutionality of the mandatory immunization of children. Even though today’s vaccines are highly effective, no vaccine is completely innocuous, therefore it is recommended to follow up with any of the negative side effects. Side effects in vaccine are majorly mild and transient. The percentage of the side effects linked with the application of vaccines is negligible in respect to the risks of complications and mortality from the disease. Even though vaccination has helped to exterminate many of the diseases; in the last two decades in the US as well as other developed European countries anti-vaccination movement has strengthened. That being said, a hugh amount of new parents are refusing to vaccinate their children. A nurse has a huge impact on improving a vaccination rate within new parents because he/she is competent enough to explain the importance of vaccination and is very close to the parents and their children.