Family ownership forms a crucial foundation for control and management in family businesses, and family involvement constitutes a significant source of heterogeneity within family firms. This study focuses on examining the relationship between the characteristics of family involvement and the performance of family firms. Empirically, the study analyzes listed family firms in Taiwan over the period from 2006 to 2019. Through investigating samples of family firms defined by various thresholds of family ownership, the findings reveal several key insights: family ownership has a significant positive impact on firm performance; the proportion of family directors on the board significantly improves firm performance; and family ownership dispersion significantly strengthens the positive effect of family ownership on firm performance. These results contribute to a deeper understanding of how family involvement affects the performance of family firms.