NIJZ has a long-standing tradition, with its activities dating back to the beginning of the previous century. On July 16, 1923, the Institute of Hygiene was ceremonially opened in Ljubljana, with Dr. Ivo Pirc as its first director. Initially, the Institute’s activities were limited to researching drinking water and providing opinions on drinking water supply. Two years later, the Permanent Bacteriological Station in Ljubljana joined the Institute of Hygiene, creating a unified institution with three departments: the Bacteriological-Serological Department, the Water and Food Testing Department, and the Hygiene-Propaganda-Didactic Department. In 1926, the Maternal and Child Health Counselling Centre and the first Health Centre were established. Soon, the Institute expanded to include the investigation and control of infectious diseases, coordination of school medicine development, development of health centres, and the organization, establishment, and supervision of all hygiene institutions in the province.
During World War II, the Institute of Hygiene produced vaccines for the partisan medical service, as well as disinfectants, disinsectants, laboratory chemicals, and other medical supplies, and dispatched them from occupied Ljubljana.
After the war, the Institute of Hygiene split into the Bacteriological Epidemiological Institute (later the Microbiological Institute of the Faculty of Medicine), where the concept of the hygiene department was formed, and the Central Laboratory for Food, which was merged with the laboratory of the city market supervision. In 1951, the Central Hygiene Institute was established, with the following tasks: to study, protect, and improve the health of the population through preventive measures; to research and improve hygiene conditions in the country; to prevent, suppress, and research infectious diseases; to develop hygiene; to direct and supervise the work of hygiene institutions. The director of the Central Hygiene Institute also served as the republic’s sanitary inspector, and the Institute included Laboratory for Food Chemistry and City Microbiology Laboratory.
In 1974, the Law on the Institute of the Socialist Republic of Slovenia (SRS) for Health Care was adopted, and in 1985, the Institute of the SRS for Health Care merged with the Institute for Social Medicine to form the unified University Institute for Health and Social Care (UZZSV). In 1992, the Institute for Health Protection of the Republic of Slovenia was established by government decree.
In 2013, the Government of the Republic of Slovenia adopted a Decision on the establishment of the National Institute of Public Health, which entered into force on 1 January 2014.