CSR is basically a commitment demanded from the companies to protect stakeholder interests, enhancement of societal conditions and contribution to sustainable development. This study investigated the relationship between corporate social responsibility and firm financial performance with a particular focus on measuring the moderating impact of ownership concentration on the CSR-performance relationship. The data is collected from the companies annual reports, State Bank of Pakistan database and Pakistan Stock Exchange for the period 2014-2020. The fixed effect regression model is used to measure the impact of CSR on firm financial performance. The results of study revealed that CSR has significant negative impact on firm financial performance. Furthermore, ownership concentration also negatively moderates the relationship between CSR and firm financial performance.