Sustainable supply chain management has become an increasingly important driver of business performance. Understanding the contingent nature of how performance is improved in this context is therefore a critical task for management. We explore the moderating effects of two practices unique to sustainable supply chain - ecocentricity and supply chain traceability - on a firm’s environmental and operating cost performance. Design: Survey data were collected from 248 UK manufacturing firms and analyzed using moderated hierarchical regression. Findings: The results suggest that green supply chain management practices are associated with improvements in both environmental and cost-based performance. Further, higher levels of ecocentricity and supply chain traceability are associated with stronger relationships between green supply chain management practices and cost performance. Contrary to expectations, high levels of supply chain traceability were found to negatively moderate the relationship between green supply chain management practices and environmental performance. Limitations: Our research design was survey-based and cross-sectional. Future studies would benefit from longitudinal research designs that capture the effects of GSCM practices on performance over an extended period. Our survey data is also perceptual; using secondary data to capture environmental performance outcomes, for example, would be another opportunity for future research. Practical Implications: We provide additional support to findings that green supply chain management practices benefit both environmental and cost performance dimensions. In this context, we show that investments by firms in working with a broader set of eco-system partners (ecocentricity) and building supply chain traceability and leads to improved environmental sustainability outcomes. We encourage managers to carefully consider how they conceptualize and monitor their supply chains. Not applicable. Originality: This paper offers several contributions to the research in this area. First, we develop and validate a measurement scale for ecocentricity and supply chain traceability. Second, we show how these two variables – unique to sustainable supply chains – can positively influence firm and environmental performance.