In this research we represent the major elements of the Theory of Constraints (TOC) in a services environment, specifically for the banking sector, and we analyze the factors involved in the decision to adopt the TOC by companies in this sector. It was identified that the four elements of the TOC theory, throughput, inventory, operating expenses and constraints, correspond to, respectively, the money coming from financial services rendered, the money required to generate this profit, the money to fund the expenses, and the limitations to the normal activity. Regarding the constraints, the most common are mainly administrative (regulations and policies) and the lack of technological resources associated to the scarcity of capital flow and the environment imposed by the state of the economy at a specific time. The main factors that influence the decision to adopt the TOC by the banking sector reside, first, in the tool's current level of development; second, in the nature and the characteristics of the banking service that are very far from the original industrial reality and, finally, in organizational factors such as the attitude towards change, the leadership of the administration and the commitment of the entire institution.