This study aims to analyze customer satisfaction and loyalty at Bank Syariah Indonesia, focusing on the perspectives of Banking Service Quality and Islamic marketing characteristics. The research was conducted using a quantitative approach with explanatory research design. Data were collected from 150 respondents selected through purposive sampling, who are active customers of Bank Syariah Indonesia and have used services for at least one year. The measurement scale employed was a 1–7 Likert scale. Data analysis was performed using Partial Least Square-Structural Equation Modeling (PLS-SEM) assisted by SmartPLS 4 software. The evaluation included measurement model testing (validity and reliability) and structural model testing (R-Square, path coefficient, and hypothesis testing through bootstrapping).

The results revealed that Banking Service Quality has a positive but weak and insignificant direct effect on customer loyalty, indicated by a path coefficient of 0.143, t-statistic of 1.272 (< 1.96), and p-value of 0.203 (> 0.05). In contrast, customer satisfaction showed a strong, positive, and significant effect on loyalty, with a path coefficient of 0.747, t-statistic of 6.433 (> 1.96), and p-value of 0.000 (< 0.05). Service quality influences loyalty indirectly through customer satisfaction, meaning that high-quality services first create satisfaction, which then leads to loyalty. The research model explains 75.8% of the variance in customer loyalty, classified as substantial. All indicators are valid and reliable, with no multicollinearity issues. These findings imply that Bank Syariah Indonesia must prioritize customer satisfaction as the main strategy to build sustainable loyalty, while continuously improving service quality and implementing Islamic marketing values such as honesty, fairness, and transparency to meet customer expectations optimally