Although in different time periods one can notice economic growth based on tourism or tourism growth generated by an economic growth (on account of the investments made in the tourism industry, for instance), the impact and importance of tourism cannot be denied, let alone the scientific interest in this field. In this context, the relationship between the number of tourist arrivals in tourist accommodation structures in Romania and the number of overnight stays was studied by applying the linear regression methodology to data available on the website of the Romanian National Institute of Statistics. Thus, it was demonstrated that 94.55% of the variation of overnight stays is explained by the variation of the number of foreign tourist arrivals in tourist accommodation structures in 2018, in counties with a low attractiveness rating (cross-sectional regression), given that the increase by one unit of the foreign tourist arrivals in tourist accommodation structures in Romania determines the increase of the number of overnight stays by 1.35 times in the respective county. This research can be extended by designing typologies at the level of counties, depending on the tourist activity and on other relevant criteria. Grouping the counties based on common criteria could facilitate a more in-depth analysis of the relationship between the number of overnight stays and the number of arrivals of tourists at county level.