This study arose due to a gap in existing research on the study of customer satisfaction in small business banking, more specifically, in the area of Trás-os-Montes, in the Caixa de Crédito Agrícola Mútuo da Terra Quente. For this purpose, a previously validated questionnaire will be applied to assess the impact of factors such as the quality of personal attention, the functioning of the branches, human resources, trust, loyalty, and feelings that influence customer satisfaction. The data will be processed using the SPSS27/AMOS27 software to estimate a structural equation model. The main contribution of this study lies in the external validity returned in the analysis of the research hypotheses on how the determinants of satisfaction influence bank customer satisfaction in a bank branch. Furthermore, it verified the importance of factors such as personal service, branch operation, trust, and loyalty in customer satisfaction, highlighting the importance of these factors and the need for some improvements to increase the satisfaction of bank customers.