We analyzed the effect of family businesses participating in the Corporate Sustainability Index on adopting Sustainable Development Goals (SDGs). Our sample consisted of 43 Brazilian companies listed in the Corporate Sustainability Index (CSI) that totaled 126 observations from 2019 to 2021. We submitted the data to exploratory factor analysis to estimate the different dimensions of the SDGs (social, economic, and environmental) that, therefore, were analyzed using panel data regression. We found that family-run companies reduce practices linked to the social dimension of the SDGs. However, the fact that the company is family-owned or has family control does not influence practices linked to the SDGs in the social, economic, and environmental dimensions. We found that family-run companies are unrelated to adopting SDG practices in the economic and environmental dimensions. Our results contribute to discussions about the environment, sustainability, investments that value socio-environmental responsibility, the activities of family businesses, and adherence to the SDGs. Especially when showing that the different characteristics of family businesses in Brazil that make up the CSI generally do not imply an increase in practices related to the SDGs. Therefore, our findings can help investors, creditors, and regulatory bodies decide on adopting socio-environmental practices.