PurposeTo investigate the relationship between a supplier and firm's level of environmental management activity and the structure of the customer‐supplier manufacturing relationship.Design/methodology/approachThis paper presents a conceptual framework and looks at the literature in order to investigate this relationship. Three main concepts (supply relationship, lean manufacturing, and environmental management practices) and their relationship to one another are described and the discussion concludes with major hypotheses for further research in this area.FindingsA major literature review reveals that efforts to improve or influence a supplier's environmental management practice raises critical issues of transaction costs and efficacy of approach for the buyer. The review allowed development of a model for approaching issues of supplier environmental performance through lean supply.Originality/valueThe environmental performance of suppliers to the supply function can prove to be a costly endeavour if not managed correctly. The framework presented in this paper may be of use in this respect.