For all the emphasis given to community-based approaches within recent environment and development policy debates, results in practice have often been disappointing both from the perspectives of implementing agencies, and of certain sections of the 'communities' concerned. This article suggests that among many possible reasons, key problems relate to shortcomings in the underlying assumptions about 'community', 'environment', and the relationships between them which inform current approaches. An alternative perspective, forwarded here, starts from the politics of resource access and control among diverse social actors, and sees patterns of environmental change as the outcomes of negotiation, or contestation, between social actors who may have very different priorities. As the authors go on to show, the notion of 'environmental entitlements' encapsulates this shift in perspective. Specifying people's entitlements and the ways they are shaped by diverse institutions offers a useful approach to the analysis of situations with which community-based sustainable development attempts to engage.