PurposeOperationalizing R-imperatives in firms is seen as vital to bolstering circularity through reduce, reuse and recycle and building circular supply chains (CSCs). However, this process introduces various uncertainties to firms within CSCs. This is a gap that still requires an in-depth analysis, particularly to answer the question of how firms align the operationalization of R-imperatives with uncertainty management to improve sustainability performance and accelerate the transition toward CSCs.Design/methodology/approachThis paper fills this gap through a multiple-case study, whereby nine firms from varying structures, regions and manufacturing industries were examined. Qualitative content analysis was employed to examine the collected primary (27 semi-structured interviews) and secondary data (internal management reports, publicly available corporate reports and website content).FindingsThe findings support the evidence that the operationalization of R-imperatives is not a straightforward process. Within-firm and SC uncertainties largely emerged and made the building of CSCs complex. Consequently, strategies aimed at reducing uncertainty were paramount to managing uncertainties and enhancing sustainability performance. For instance, implementing durable or modular designs helped firms easily reuse, repair and recycle products. In turn, firms achieved material efficiency and contributed to extending the life cycle of products.Practical implicationsThis paper explains how firms can align R-imperatives operationalization with uncertainty management to improve sustainability performance and enhance CSCs. Accordingly, firms should complement R-imperatives operationalization with proactive uncertainty management and an assessment of all environmental, economic and social sustainability dimensions.Originality/valueThis paper fills a critical gap in circular supply chain management literature by unveiling its linkage with uncertainty management and sustainability performance. Empirical insights from nine firms within CSCs are provided to guide scholars and managers interested in implementing R-imperatives.