Materialism has often been pitted against relational well-being. However, it is unclear if such a negative relationship exists in East Asian cultures where personal goals and values tend to be shaped by social motives. In three studies, we tested the association between materialism and relational well-being across multiple individualistic and collectivistic cultures and further studied the role of social motives for materialism. In Study 1a, materialism predicted relational well-being negatively in the US but not in Japan. In Study 1b, we replicated the findings of Study 1a with Chinese and the US adults showing that materialism predicted relational well-being differently between the two cultures. Lastly in Study 2, Chinese reported higher social motives for materialism than European Americans, and such difference explained cultural moderation of the link between materialism and relational well-being. The studies suggest that cultural contexts and social motives play important roles in relational well-being of materialistic individuals.