Research background: Gambling is a specific activity that has an undoubtful impact on the national economies, however the evaluation of this sector still has been analysed very little by economists. This article comparatively analyses the peculiarities of the gambling sector activity in Lithuania, Latvia, Slovak Republic and Czech Republic in the period from 2015 to 2020. Purpose of the article: The purpose of the article is to evaluate the activity of the gambling sector in Lithuania, Latvia, Slovak Republic and Czech Republic. Methods: The following methods are used in the article: comparative analysis and synthesis of scientific literature and legal acts, analysis of graphical and statistical data. Findings & Value added: An analysis of scientific literature and legal acts revealed that definition of gambling is defined differently and in some countries certain types of gambling are not even considered as gambling or does not exist. The evaluation revealed that during 2015-2019 the highest AAGR of the gambling sector’s GGR was in Latvia (11.09%) and in 2019 Latvia also had the highest GGR per inhabitant 199 Eur. On the contrary, during 2017-2019 in the Czech Republic AAGR of the gambling sector’s GGR was -5.63% and in 2019 GGR per inhabitant (39.51 Eur) was the lowest. According to the mentioned statistical data, total GGR and the population size, Latvia has one of the largest gambling sector in the evaluated countries, so gambling sector in other countries still has great potential to growth. Although because of COVID-19 Latvia experienced huge losses of GGR, Slovak Republic online gambling sector showed a great potential to grow and it can be assumed that in Lithuania online gambling sector didn’t took over all of the potential revenue from land-based gambling sector.