Many earlier studies conducted on sports betting and addiction have examined sports betting in the context of gambling and have not taken into account the specific motivations of sports betting. Therefore, the effects of motivational elements of sports betting on sports betting addiction risk are unknown. The aim of the present study was to examine the effects of motivation factors specific to sports betting on sports betting addiction. Accordingly, three linked studies were conducted. Firstly, to determine sports betting motivations "Sports Betting Motivation Scale (SBMS)" developed and validated. Secondly, to determine the risks of sports betting addiction "Problem Sports Betting Severity Index (PSBSI)" was adapted from Problem Gambling Severity Index (PGSI). Finally, the third study examined effects of the sports betting motivations on sports betting addiction risk. Study one (n=281), study two comprised (n=230), and the final study comprised (n=643) sports fans who bet on sports regularly for 12 months with different motivations. The findings demonstrate that the SBMS appears to be a reliable and valid instrument for assessing sports betting motivations. Also, the findings provided PSBSI validity for the use of the Turkish and sports betting adapted version of PGSI. As a result of the main research, "make money," "socialization," and "being in the game" motivations were found to be positive predictors of sports betting addiction risk, while "fun" motivation was a negative predictor. The motivations "recreation/escape," "knowledge of the game," and "interest in sport" were found not to be significant predictors of the risk of sports betting addiction.