Purpose The purpose of this study is to add insights into the business-to-business (B2B) branding literature by investigating the mechanism by which brand orientation affects relational performance in the B2B context. Design/methodology/approach A theory-based model is developed and tested using data collected from 201 Chinese B2B companies. Partial least squares analysis is used to test the hypotheses. Findings The results suggest that relationship commitment serves as an important means that translates a firm’s brand orientation into superior relational performance. Moreover, this positive effect is more prominent when the supplier is co-branding with its buyer. In addition, state-owned buyers are more inclined to develop affective commitment than calculative commitment when their suppliers are brand-oriented. Research limitations/implications This study examines the research questions from only the buyer side. In addition, the causal interface of the results might be limited due to the cross-sectional nature of the data. Practical implications While brand orientation generally leads to enhanced relational performance, it depends on the buyer’s involvement in co-branding and its ownership structure. Originality/value This study is among the first to uncover the underlying mechanism by which brand orientation adds value to B2B relationships. The findings provide compelling insights for managers who are interested in promoting a brand orientation to improve relational performance within their organizations.