Business model (BM) literature has developed considerably; however, most research takes place in large for-profit organisations in western settings, rather than small–medium enterprises with social goals. This is surprising given the drive for social innovation (SI) and alternative modes of organizing. Models for managing innovation are typically agnostic about sources of social, ecological and cultural values; yet our in-depth qualitative research demonstrates that, for SMEs practicing SI in Vietnam, these values are as inherent as economic value. As a result, a new social BM emerged and was evaluated. This paper: (i) defines a Business model for SI for sustaining the long-term growth of SI; (ii) provides a Strategic framework for SI for SMEs, to ensure that the strategy of SMEs takes into consideration the positive impact SIs can have on society; and (iii) defines mechanisms to create and capture economic, social, cultural and ecological values.