The social dimensions of innovation are examined for a group of manufacturers in Mwanza, Tanzania. Social networks of businesspeople in Mwanza are found to support innovation in manufacturing firms. Trust in these relations is especially important as it improves the quality of information exchanges and encourages the development of strong intracommunity ties and weak intercommunity relations. A typology of manufacturers demonstrates how different social strategies relate to innovation. The findings suggest that openness to social relations enhances innovation but that weak formal institutions discourage manufacturers from extending their social relations beyond core networks.