Casino gambling in the Obalno-kraška region has had a long tradition, its origins dating back to the beginning of the 20th century. Ever since its rebirth during Yugoslav times in the 1960s, casino tourism has contributed significantly to the development of the area. Until recently, casino tourism has been one of the most important forms of tourism in addition to 3S and congress tourism. The purpose of this paper is to determine the contribution of casino tourism to the regional development of the Slovene Istria. To this end, selected socioeconomic indicators were examined and compared with the average indicator rates of regional development at the national level. The results show that casino tourism is an important factor of regional development. However, casino tourism’s future role in regional development remains an open question due to the impacts of the financial crisis and the consequent decline in the number of guests, as well as reduced levels of investment in the region.