The development of Sharia products has become a trend in consumer awareness of life and confidence in the value of the benefits offered. This research aims to determine the effect of trust on customer loyalty through customer satisfaction. The method in this study is the SEM Smart PLS model. The population and sample in this research are 329 customers of PT. Bank Syariah Indonesia Branch Range was selected by accidental sampling. The research data was obtained through a questionnaire arranged based on each research variable's indicators. The results of this research show that trust directly has a significant effect on customer satisfaction, and trust has no significant effect on customer loyalty. Then indirectly, customer satisfaction is essential in mediating trust in customer loyalty. The implications of the findings in this study indicate that customers feel uncomfortable with the many telemarketing programs carried out by employees of PT. Bank Syariah Indonesia Cabang Kisaran because this is considered a problem of wasting working time.