Simple SummaryLactoferrin is a whey protein with a high health-promoting potential, also in the context of civilization diseases such as obesity and type 2 diabetes. It is perfectly suitable as an addition to fermented milk drinks—yoghurts, which are easily acceptable in the diet. As a natural milk protein, it is perfect for increasing the health-promoting value of yoghurts. The results obtained from the physicochemical, microbiological, and organoleptic assessment of yoghurts indicated that the use of yoghurt fortification with lactoferrin in the amount of 80 mg/100 g in most cases did not statistically significantly affect the analysed parameters. Yoghurt with the addition of lactoferrin was fully acceptable by the testers.AbstractThe stability of fortified yoghurts during refrigerated storage is important for industry and the consumer. The aim of the study was to evaluate the nutritional value, microbiological quality, organoleptic properties, and structure of natural yoghurts made with the addition of lactoferrin during refrigerated storage. In this study, we produced natural yoghurts fortified in lactoferrin, using YC-X11 yoghurt starter culture based onLactobacillus delbrueckiisubsp.bulgaricusandStreptococcus thermophilus. Physicochemical (acidity, nutritional value and structure) as well as microbiological and organoleptic changes occurring during 28-days refrigerated storage were determined. Storage research made it possible to determine the direction of changes taking place in the products. The analysed parameters did not differ statistically significantly between the control yoghurts and those with the addition of lactoferrin. Textural and rheological studies also shown that the addition of lactoferrin did not significantly change the structure of the yoghurt. The yoghurts were characterized by high sanitary and hygienic quality during the whole refrigerated storage. Lactoferrin has a positive effect on the durability of the product.