Few studies try to understand how the unique preferences of family firms affect tax strategies, and how family firm heterogeneity drives variation in tax activities. Drawing on the mixed gamble approach, this study examines the tax aggressiveness of different types of family firms, considering how various sources of heterogeneity alter the perception of potential gains and losses to socioemotional and financial wealth. Based on a panel dataset of 242 private family firms for the period 2012–2014, this study shows that strong family‐owned firms, family firms with a family CFO, family‐founder firms, and family‐named firms display lower levels of tax aggressiveness. These findings demonstrate that family firm heterogeneity is a crucial factor in the mixed gamble calculus of tax aggressiveness.