SUMMARY
Buyers and suppliers of healthcare products and services are more dependent on each other than ever before for the provision of scarce and unique resources, which highlights the need to implement supply chain sustainability practices. Firms controlling these resources hold excessive power over others. This study adopted resource dependence theory as a theoretical lens to explore the role of relationship power in supply chain sustainability practices between a South African private healthcare provider and its suppliers. The study employed a generic qualitative single-case study design. Semi-structured interviews were used to collect data from 12 participants at various levels of the case organisation’s hierarchy. The main findings revealed several types of environmental and social practice used in the supply chain of the private healthcare provider. Some of the environmental practices were effective waste management and recycling, while the social practices included supplier selection and periodic reviews. The healthcare provider exercised extensive power over its suppliers to implement these practices. By exploring the advantages and disadvantages of sustainability practices, the findings showed that relationship power acted as a driver of supply chain sustainability. Mutual commitment, continuous communication, and training support these practices. Healthcare managers must be aware of the importance of relationship power for supply chain sustainability practices implementation, and are advised to invest time and effort in building buyer—supplier relationships to aid sustainability. This study expands the literature on relationship power in supply chain sustainability practices in an underexplored developing country healthcare context.