Research on innovation in family firms has been increasing recently; however, the results are mixed, especially for non-listed firms. Based on internal social capital, we explore whether the relational antecedents of innovation are contingent on family involvement in management. Using a sample of 172 Spanish family small and medium-sized enterprises – an organisational form with prominent social and emotional factors – we test a structural model that examines the influence exerted by family involvement in the top management team on the relationships between innovation and internal social capital – in the form of family social capital and non-family social capital (family group and non-family group, respectively). The empirical findings obtained using the partial least squares technique show the importance of family involvement in management in such relationships in family firms. Family involvement in management was found to have negative effects in the relationship between internal social capital and innovation.
