Abstract: The goal of this research is to determine the role of social media involvement as a moderating variable in the link between brand commitment and customer retention for smartphone businesses. The  study is a conclusive descriptive research and employs a deductive technique. The study utilizes the regulatory engagement theory to investigate the proposed research model in the egyptian smartphone industry context. The study  targeted a sample of 317 undergraduate students from the faculty of business at Ain Shams University. Structural equation model (SEM) was used to test the conceptual framework in this research. The study focused on the affective and continuance brand commitments as two key positive paths to customer retention. The results indicate that customer engagement positively influences the relationship between brand commitment and customer retention. In addition, affective commitment exceeds continuance commitment in term of customer retention.