Maintaining customers and keeping them loyal is considered vital for continuing business. In this study reported
here examines the effect of four underpinnings of relationship marketing – trust, commitment, communication,
and conflict handling – on customer loyalty in Iran. This research is a descriptive study done by survey method.
The population in this study includes 400 costumers of private and state banks in Sanandaj of Iran. The
instrument of data gathering was a questionnaire and the data were analyzed based on regression. Findings show
that dependent variable is related to the independent variables meaningfully and positively.