Abstract Research on the relationship between family involvement and eco‐innovation presents conflicting results. To address this issue, this study explores the role of family involvement in eco‐innovation by dividing it into pollution prevention and cleaner production types. We propose that family involvement positively relates to pollution prevention eco‐innovation, but negatively relates to cleaner production eco‐innovation. Moreover, we explore the boundary conditions of the proposed relationships. We also contend that internal social capital positively moderates the relationship between family involvement and eco‐innovation in both types of eco‐innovation, while external social capital exhibits positive and negative moderating impacts on pollution prevention and cleaner production, respectively. Data from Chinese listed firms from 2007 to 2019 support these arguments. This study adds to the family business research and eco‐innovation literature by providing a more comprehensive view of the role of family engagement in eco‐innovation.