Most of the theoretical and empirical research into brand equity has focused on business to consumer relationships and the value created with end-customers (consumer-based brand equity). Little is known of the processes where brands create value in business-to-business relationships such as in manufacturer-retailer relationships. This article reports the qualitative findings of a research project into this under-researched area investigating the role of brands in business-to-business relationships. The results show that manufacturers’ brand equity is linked to the value of the brand performance as perceived by the retailer. This perceived value has an impact on key relationship variables such as commitment, trust, dependence and cooperation. To obtain the optimal value from the brand, both manufacturers and retailers need to manage these sources of brand asset value within the business relationship. Although large brands have considerable influence in the relationship, smaller brands can also offer value to retailers and play an important part in the management of product categories within the store. A conceptual model is developed that shows the impact of the sources of brand value within a business-to-business relationship.