PurposeThis study aims to facilitate the development of a better understanding of how controlling shareholders respond to the mandatory system of corporate governance rating (CGR) for all firms listed on Taiwanese stock markets and the incentives of controllers to apply corporate governance best practices.Design/methodology/approachUsing CGR data for all Taiwanese listed firms from 2014 to 2020, this study examines whether controlling shareholders determine a firm’s CGR.FindingsSingle-family-controlled firms have the lowest CGRs, and management-controlled firms have the highest ratings. Blockholder-controlled firms are more likely to have top 20% ratings than single-family-controlled firms and bottom 20% ratings than single-family and management-controlled firms. All three categories of firms have unfavorable (favorable) ratings because of substitute governance effects (signaling effects).Originality/valueManagement-controlled firms, in which agency problems refer to principal-agent conflicts, are more likely to have good ratings than single-family controlled firms, in which agency problems refer to principal-principal conflicts. Blockholder-controlled firms have extreme ratings, suggesting that multiple large shareholders develop corporate governance practices consistent with their best interests to increase firm value or expropriate wealth. Low cash flow rights and high control-ownership divergence lead firms to adopt additional governance arrangement(s) to make shareholders trust firms with capital and signal to shareholders that they can trust them with their capital.