Outsourcing relationship quality (ORQ) has shown to be an important construct in previous research on outsourcing effectiveness. But, while there are various works that have conceptualized and operationalized ORQ as a rich and multi-dimensional construct, other studies which consider ORQ as (usually mediating) component of their theoretical models make hardly use of those works but often use less rich constructs. The research on hand attempts bridging the gap between those two groups of works. A multi-dimensional ORQ construct is used to evaluate the relative importance of different ORQ dimensions, such as commitment, trust, etc., in regard to different dimensions of outsourcing success (overall satisfaction, goal achievement, service quality). For example, while many studies use trust as proxy for ORQ, our study shows that, depending on the outcome variable, other ORQ dimensions might be more relevant and should be used instead or additionally. Thus, the main contribution is identifying those ORQ dimensions which are most relevant regarding different outsourcing success variables. Future studies on outsourcing success factors will have a better ground to argue for or against using certain ORQ dimensions in their studies. Moreover, the study sensitizes managers for different distinct ORQ dimensions and their importance for a successful outsourcing relationship.