By integrating literature on family functionality, family firms, and socioemotional wealth (SEW), we develop a theoretical model explaining how family functionality and SEW dimensions influence firm innovativeness. Our multigroup structural equation model on two samples of family small and medium-sized enterprises (SMEs) shows that family functionality is positively linked to SEW, whereas divergences emerge on the effect of different SEW dimensions on innovativeness. Binding social ties, the emotional attachment of family members to the firm, and the renewal of family bonds through intrafamily succession positively affect family SME innovativeness, while identification of family members with the firm has a negative effect. By deepening current understanding of the role and functionality of controlling families as determinants of their propensity to preserve SEW and achieve innovativeness, our findings offer important implications for theory and practice, paving the way for future research on SEW and family firm innovation.