This paper examines the diffusion of corporate environmental practice in the context of field level dynamics. It builds a conceptual model that makes links between (1) the complex constituency of the institutional field driving environmental concerns, (2) the multiple cultural frames that emerge from that constituency, and (3) the corresponding structural and cultural routines that become enacted within firms. It offers contributions for research in the domains of both environmental practice and institutional theory. For environmental practice, this paper attends to the genesis and diffusion of environmental practice that go beyond individual organization level. For institutional theory, this paper moves beyond the traditional focus on isomorphism and elaborates the processes of field-level dynamics. It shows how field level heterogeneity can occur by depicting inertia, traditionally a phenomenon attributed to the field, as the result of individual organization level dynamics that resist change. The paper concludes with ideas for future research.