Istria is located in the west of Croatia and represents our largest peninsula. It stands out with its specific geological structure. We can get an insight into the geological structure of the Istrian County using the basic geological maps. Considering that landslides occur in areas where there are soft rocks or soils whose characteristics are low strength and high susceptibility to deformation, the areas of Istria built from flysch rock mass or flysch deposits belonging to the type of soft rocks are read. These are areas located in the northeastern, northern and central parts of the peninsula. Landslides in that area were triggered by hydrological conditions, while the geological structure was a key prerequisite for the landslide in combination with anthropogenic causes. This paper provides a brief overview of the prerequisites and drivers of landslides, an overview of the geological structure of Istria through geological periods throughout history, and the spatial distribution of flysch deposits in Istria, and based on this distribution, an insight into landslides in the area and an analysis of the engineering geological models of the Brus, Pićan and Juradi landslides which are located in Istria.