Retaining structures, most commonly retaining walls, are used to maintain the stability of various slopes and unstable embankments. This paper is based on the analysis of different theories of soil pressure development, a description of the types of retaining walls encountered in practice, various methods for calculating the stability of such structures, and a practical example. The choice of the type of retaining wall may depend on factors such as: the method of construction, its durability, load-bearing capacity, load distribution, material, mechanical behavior, site conditions, and other required characteristics and on-site needs. Retaining walls must be properly designed and dimensioned to prevent unacceptable deformations of both the wall and the retained soil. With superior design, potential failures are avoided, enabling the construction of new buildings on otherwise challenging terrains. The paper will show what factors affect the dimensions of retaining walls and how to handle the final results of stability analyses for sliding and overturning. It will present the approaches used to determine the stability of retaining walls, highlighting which approaches yield more conservative results compared to others, as well as the other key differences between them. The classical theories of Rankine and Coulomb form the foundation for determining soil forces, which precede all stability analyses for sliding, overturning, and other failure mechanisms that will be discussed in the paper. The differences between Rankine’s and Coulomb’s classical theories and other theories must be presented through the theory of allowable stresses, as well as the modern approach via Eurocode 7. The application of all the discussed theories will be demonstrated through a calculation example of a gravity retaining wall and its stability under the effects of given loads. The calculations will be performed manually using analytical methods and compared with results from the GEO5 software. The conclusion will be based on the obtained stability results and their implications for choosing the appropriate approach for retaining wall calculations.