Gambling activity is a multifaceted phenomenon. Gambling is a special field of business. The government authorities ascribe the right to a monopoly of this area of economic activity. The randomness and financial size of gambling foster the development of the grey market. In addition to the economic effect, the moral dimension of this type of activity is an extremely important aspect. The Customs and Tax Control Service supervises the functioning of the gambling market in Poland. Subject and purpose of work: The article is devoted to the issue of gambling. The aim of the research was to present the activities of the Customs and Tax Control Service in the field of legal and illegal gambling. Materials and methods: The study methods used were literature review, legal acts, documents of the Ministry of Finance, statistic data, using quantitive and systems analysis. Results: As a result, the directions of the Customs and Tax Control Service activities were identified in the field of gambling market control. Conclusions: The activities of Customs and Tax Control Service bring results in fighting illegal gambling, protecting players, and raising social awareness of the dangers of using services of illegal gaming operators.