With the growing intersection of entrepreneurship, development and foreign aid, international base-of-thepyramid ventures (IBOPVs) become increasingly important. Originating in developed economies, they target markets and beneficiaries in developing economies with impact-oriented products and services. We study how entrepreneurial ecosystems (EEs) in developed economies can support IBOPV formation. Based on the case of Greater Boston, we identify three critical EE infrastructures supportive of IBOPV formation: (i) IBOPV launch spaces, such as research projects and entrepreneurship courses, where participants create new ventures around innovation for development, (ii) network-based BOP knowledge infrastructures that provide entrepreneurs with technological, BOP market, and business model knowledge, and (iii) alternative funding networks that connect IBOPVs with regional investors, global development organizations, and entrepreneurship support organizations in emerging economies. However, we also find that relevant ecosystem infrastructure services can be fragmented so that potential synergies and spillover effects are not generated automatically. It takes effort of support organizations and IBOPVs to enact, mobilize, and combine infrastructure services in order for EEs ' IBOPV support capacity to materialize. This study has critical implications for research on IBOPV formation and EEs supporting social entrepreneurship in the context of poverty.