Irrigation is an agrotechnical measure that is important for the Mediterranean area, and its significance will increase in the future if droughts and high temperatures continue to occur more frequently. Olive (Olea europaea L.) is a crop that is very widespread in the Mediterranean and well adapted to the climatic conditions of the Mediterranean area, however, to achieve optimal quality and adequate yields, irrigation is required. The aim of the work was, in addition to the irrigation rations and the moment of the start of irrigation, which were defined during the implementation of the SAN project, to determine the quality of irrigation water by comparative analysis of individual samples, years and locations of sampling. Within the SAN project, irrigation water analyzes were carried out at two locations, an olive grove in Žman and an olive grove in Novigrad. Samples of 1 L were taken during July, September and November in 2019, and in 2020 during April, July and September from the irrigation system and delivered to authorized laboratories where water analysis was done. According to water analyses, selected chemical parameters of water quality were determined: irrigation coefficient (Ki), SAR value and electrical conductivity (EC). A descriptive statistical analysis of the comparison of measured values of water quality parameters was performed. By comparative analysis of the average values of irrigation water quality parameters according to locations and years, the irrigation water at the Žman location in 2019 had the highest values of the irrigation coefficient (48.61), the highest SAR values (124.48) and the lowest electrical conductivity (0 .31 dS/m) while the highest determined electrical conductivity (39.28 dS/m) and the lowest irrigation coefficient (5.03) were in 2019 at the Novigrad location, and the lowest SAR value (35.75) was in 2020. at the Novigrad location. The use of saline water in irrigation can have long-term negative consequences, therefore it is very important to carry out further analyzes of water quality and to use only water of appropriate quality according to parameters that have been determined in advance. The determination of Ki, SAR and EC is especially important for the Mediterranean area, since there is a frequent occurrence of saline or alkalized waters in that area.