Purpose: This paper explores how organizational capabilities and path dependence affect the implementation of supply chain (SC) sustainability initiatives. Through the lenses of contingency and evolutionary theory, the paper addresses the underexplored supply chain dynamics that enhance or inhibit sustainability trajectories.Design/methodology/approach: Using in-depth multi-case studies for theory elaboration, five supply chains were studied through open-ended interviews with SC members, secondary data collection and site visit observation. The design consists of a combination of deductive and inductive approaches to elaborate theory on supply chain dynamics and enhanced sustainability trajectories.Findings: The empirical study shows that learning is a fundamental condition for supply chains as they implement sustainability initiatives, and that exploitation capabilities are more frequently used than exploration capabilities. Path dependence plays a role in the outcomes of supply chain sustainability initiatives, which are influenced by both path dependence and contingencies of the contexts in which these systems operate.Research limitations/implications: This paper puts forward five propositions that emerge from the literature and from the field study results. Although this is an exploratory research bounded by geographical limitations and the limited number of SC cases, the goal of elaborating theory may open up several promising avenues for future large-scale and longitudinal research studies.Practical implications: By enhancing our understanding of the dynamics of supply chain sustainability trajectories, decision-makers, scholars and policy-makers can better understand how supply chains learn, how they employ SC member capabilities and how they deal with stakeholder resistance.Originality/value: This paper extends supply chain sustainability theory by addressing the knowledge gap that exists with regard to understanding the dynamics of evolving supply chain sustainability trajectories. This paper sheds additional light on this important topic and contributes in multiple ways to the sustainable supply chain management literature.