Rapid developments of the internet and the increasing growth of social media have provided new opportunities for today's businesses. Using these media, organizations can build up deep and lasting relationships with their customers. Moreover by engaging customers with their brand, they can create positive outcomes for themselves, customers and society. Accordingly, this study seeks to identify Antecedents, dimensions, and consequences of customers brand engagement in social media in the banking industry. In order to achieve the goal, In-depth interviews were conducted with customers who following one or more banks on social media, and data analysis was performed by using content analysis method. The results of the research were presented in a research model consisting of three divisions of Antecedents (individual, organizational and media), consequences (individual, organizational and social) and dimensions of customers brand engagement. Finally this study provided suggestions to use these media to engage customers.