Purpose This study aims to investigate the key roles of human and relational capital in the export orientation and competitiveness of knowledge-intensive cooperative companies. It is also aimed to examine the moderating role of marketing knowledge capabilities. Design/methodology/approach Data from 552 managers at 86 companies, selected from knowledge-intensive export cooperatives, were analyzed with structural equation modeling with the partial least squares approach. Findings Results indicate that both human and relational capital exert considerable effects on competitiveness. Export orientation was a driving factor for cooperatives’ competitiveness. Human and relational capital fostered the effects of export orientation on competitiveness. Moreover, marketing knowledge capabilities were found to moderate the relationships between human and relational capital and export orientation, as well as between export orientation and competitiveness. Originality/value By highlighting the role of human capital and relational capital in export orientation and competitiveness, this study offers an analysis of important managerial processes within cooperative companies, which have not been sufficiently addressed in previous research. This research also demonstrated the moderating role of marketing knowledge capabilities in strengthening relationships between human and relational capital and export orientation, as well as between export orientation and competitiveness, which has been neglected in previous studies. These findings provide academics and practitioners with a new framework for examining the relationships between these constructs, which will enable them to establish strategies for achieving a competitive advantage.