Sustainable entrepreneurship, that is, venturing with the aim of contributing to a shift of practices towards environmental and social sustainability, is an increasingly prominent phenomenon. This article investigates how sustainability ventures orient between dual – commercial and environmental – logics when conducting the legitimation work necessary to secure their first major partnership with an incumbent firm. Specifically, we study multiple cases of partnerships on food waste reduction. This setting is characterised by limited tension between the two logics, which implies that ventures are not forced into hybridity. We find some indications that ventures are able to draw on both types of logic to legitimate their ventures. However, the dominant pattern is that sustainability ventures tend to orient their legitimation work around a salient founding logic. Our analysis suggests that this pattern can be attributed partly to organisational imprinting, but also to legitimation work in this context being inherently logic-specific to a significant degree. This seems to be particularly true for ventures with a salient environmental logic. .