The authors conduct a meta-analysis to examine dependence and interdependence in marketing relationships. Analyses reveal that dependence affects performance primarily through relationship quality and cooperation, while interdependence has substantial direct effects as well as effects mediated through relationship-specific investments and cooperation. Regarding relationship context, effects of dependence are stronger in channel relationships than end-user relationships and for services than goods; interdependence does not display the same pattern. Regarding methodological context, dependence measures that emphasize relationship value versus switching costs have different moderating effects; greater general dependence content is associated with weaker effect sizes for dependence but conversely greater effect sizes for interdependence. These results suggest that new insights can be gained by distinguishing relationship value and switching cost components of dependence and by investigating the possibility that the conceptual domain of interdependence differs from that of dependence. Future research that strives for greater precision in the measurement of dependence and interdependence constructs and that simultaneously examines dependence and interdependence is recommended.