The gambling market is expanding and growing every year, both worldwide and in the Republic of Croatia. This is influenced by the increasing liberalization of the market, new technologies that enable easier and faster access to gambling of chance and aggressive advertising of game organizers. Digitization contributes significantly to the growth of the market, as online casinos, online betting and lotto games players can now play wherever they are via their personal computers or mobile phones. With the expansion and liberalization of the market, there are more and more attempts at tax fraud, attempts at money laundering, as well as increasing dependence, especially among younger people. Supervision over the organization of gambling is carried out by the Tax Administration as a unique and independent administrative organization in the system of the Ministry of Finance. In addition to the usual tasks of the Tax Administration determine tax liabilities, collection, recording, processing and verification of data relevant to determining the tax base, and analyzing data on accounting taxes, in supervising the organization of games of chance The Tax Administration has a specific role related to: prevention of money laundering and terrorist financing where it appears as a supervisory body over the obligors who are engaged in organizing gambling, protection of minors from gambling addiction, as well as detecting and banning illegal gambling. In this final graduate thesis, it will be explained what gambilng is, who can organize it and under what conditions, which includes supervision over the organization of gambling.