The research investigates the influence of corporate governance and corporate social responsibility (CSR) on the financial performance of manufacturing firms in Indonesia, finding that corporate governance has no effect, while CSR positively influences financial performance (measured by ROA) but negatively affects it when measured by Tobin's Q. The study uses efficiency as a mediating variable, emphasizing that while CSR can enhance financial performance, its impact varies based on measurement and context. Through a quantitative approach, the analysis is based on data from 297 firm-year observations from 2009 to 2012.