The author critically evaluates the impact and potential of a community currency—or local money system—known as the ‘local exchange trading scheme’ (LETS), to contribute to sustainable local development (SLD). Two distinct and contrasting models for sustainable development are described: a mainstream approach, focused on local regeneration [termed here the ‘local economic development’ (LED) approach]; and a radical ‘green’ or ‘new economics’ strategy (referred to as ‘sustainable local development’ or SLD). In the elaboration of these models the functions of community currencies within each perspective are outlined, and the basis for an evaluate framework is provided. Most previous analysis of LETS has used a broadly LED perspective; this paper focuses on an evaluation for SLD, as this has not previously been comprehensively done. For SLD, community currencies should enable people to: meet local needs through informal employment; revalue and redefine ‘work’; promote localisation and self-reliance; shift consumption patterns towards sharing, recycling, reuse, and reducing resource use; and build green social networks. Findings from a case-study LETS indicate that this community currency is successful in allowing participants to make small changes in their lifestyles, consumption, and employment patterns towards SLD, but there are limitations of size, scope, funding and management to be overcome before this could be achieved more effectively with LETS. However, following the LED-relevant prescriptions for upscaling and mainstreaming would undermine the qualities which align LETS with SLD perspective, and this highlights the importance of choosing appropriate evaluative frameworks, particularly when appraising sustainable-development initiatives.