Objective: The objective of this thesis is to examine the movement of acute intestinal infections (AII) with special reference to the infections of non-alimentary way of transmission and the risk of their transmission due to the corresponding water supply facility from the year 2005 until 2014 throughout regions of the Split-Dalmatia county. Material and methods: Using a retrospective study the morbidity of acute intestinal infections was compared between primary health care which was determined on the basis of registration of infectious diseases and hospital morbidity which was determined on the basis of discharge papers of hospitalized patients. Comparative epidemiological method was used to compare morbidity of acute intestinal infections between the branches/regions of Split-Dalmatia county and between their respective water supply facilities. Results: In total, in all areas/branches of the Split-Dalmatia county, there is a downward trend of patients hospitalized due to acute intestinal infections. The classic intestinal anthroponoses are registered only as imported forms of the disease. The mortality rate is extremely low 0.20/100,000 (from total of nine deaths two of them were children under the age of four). Statistically, the greatest rates of morbidity are with the inhabitants of the youngest age. Comparing the morbidity established on the basis of registration of infectious diseases and of that based on hospital discharge papers, there is no difference between the branches/regions of the Split-Dalmatia county or between areas with corresponding water supply facilities. Statistically, the lowest morbidity rates of AII with non-alimentary way of transmission are amongst the inhabitants of areas where the water supply facilities use surface water from the Cetina river: the regional system of the Makarska littoral 24.19/100,000 and the regional system of Omiš-Brač-Hvar-Šolta 35,51/100, 000. The highest morbidity rates are amongst the inhabitants of areas with small water supply facilities: VS Marina 62,74/100,000 and VS Vrgorac 62,45/100, 000. The only two epidemic outbreaks of waterborne AII in the last ten years were recorded in inhabitants of VS Vrgorac caused by viruses (Norovirus and Rotavirus). The cause of the epidemic outbreaks was a technical flaw in chlorination of water for human use because of the lack of an automatic gas chlorinator. Large water supply facilities that use water from river sources without water purification have higher rates of hospitalization for AII with non-alimentary way of transmission of the corresponding population than the water supply facilities that use surface water of the Cetina river. Statistically, the residents of the largest RS-Solin-Split-Kaštela-Trogir have a significantly higher rate of hospitalizations-58,94/100,000, than the county average, while in others the increase has no statistical significance. Conclusion: In modern cosmopolitan conditions of rapid AII pathogen interchangeability due to major migrations, tourist travel and climate change, clean water for human consumption requires more attention. In particular, the attention should be directed towards the preservation of purity of the surface waters in the karst hydrogeological regions by purifying waste and sewage waters before their discharge into the receiving waters of river watercourses. Increased tourist activity in dalmatian hinterland of Split-Dalmatia county without proper purification of waste and sewage waters represents additional security threats for the residents of the entire county.The current, still favourable state of security of water supply, needs to be modernized with the new modern approach in the supervision of AII, using methods such as laboratory microbiological pollution monitoring, the new PCR-real time technologies and the modern electronic prompt patient alerts by their areas of residence.