This paper aims to analyse the religious structure and its evolution in the Apuseni Mountains (Romania). Thusly, we employed statistical data from three distinct population censuses, the first one being the Austro-Hungarian census of 1880. The next one was the one in 1930, organised by Romanian authorities. Furthermore, it was the first and most important demographic census after the Great Union of 1918. The last census taken into consideration was the one in 2011, the second census of the 21st century. After obtaining the numerical data from the three censuses, we processed it using Microsoft Excel. Three tables were generated, emphasizing the numerical values and the percentages for each religion or confession for each census. The map depicting the geographic location of the study area was developed using GIS technology (ArcGis 10.3). We determined that Christians have been dominating the Apuseni Mountains and the Orthodox faith had and still has the most adherents. Likewise, the political-administrative factor heavily influenced census operations and also produced imbalances in the religious structure, especially after the 1948 abolition of the monarchy.