Purpose: Several development organisations have implemented programs to enhance smallholder farmers’ crop productivity and market access through collective action with mixed results. Therefore, this study examines the drivers of success of collective action initiatives as a pathway to improving farmers marketing performance using data from Rwanda and the Democratic Republic of Congo. Design/methodology/approach: This study uses primary data collected from 30 farmer groups through focus group discussions. These groups are assessed for differences in their marketing performance using descriptive and cluster analysis techniques. Findings: Most of the group members are poor (67%) and few are considered as rich (2%) or middle class (28%), while the rest are destitute. The destitute community members are often excluded from the groups due to their own passivity and inability to contribute financial resources for joint activities. Mature farmer groups with strong internal structures and greater participation in product bulking as well as formally organised groups with stable external links significantly have higher marketing performance. Practical implications: We recommend that for farmers to maximise the benefits of collective action, supportive policies are necessary to encourage the formation of groups and transform existing ones into business entities to access high-value markets and perhaps even export markets. Farmer groups need to intensify their market research to access ready and stable markets such as supermarkets and institutions with larger volumetric requirements. Theoretical implications: The study shows that collective action is important for smallholder farmers in developing countries to sustainably access markets and increase their marketing performance. Originality/Value: Few studies have examined how social capital and collective action are utilised to improve smallholder farmers marketing performance, particularly in Central Africa.