The environment has become an increasingly prominent consideration across the third sector in the UK. However, while there has been an ‘audit explosion’ in relation to demonstrating the social mission of third sector organisations (TSOs), this has not transferred to the management of environmental impacts. This paper offers the first assessment of the development and adoption of environmental management systems (EMSs) across the third sector. Through a comparison with the experience of the private sector, analysis of key documents, interviews with third sector and government actors, and case studies of TSOs that have applied and/or adapted EMSs, the paper provides evidence of a relatively low level of innovation in this area. The paper concludes with reflections on the tensions associated with the future development of EMSs across the third sector, in particular the ambiguous role of government policy.