The purpose of the present study is to investigate the relationship between corporate social responsibility and investment efficiency with particular emphasis on the mediating role of agency cost and information asymmetry in a sample of 121 firms listed on the Tehran Stock Exchange during the time period from 2012 to 2017. The research hypotheses are tested using multivariate regression analysis based on panel data and Eviews software. The results indicate that corporate social responsibility is negatively correlated with investment inefficiency. In other words, corporate social responsibility leads to reduced investment inefficiency. Also, information asymmetry plays a mediating role in the relationship between corporate social responsibility disclosure and underinvestment, whereas the variable of agency cost mediates the association between corporate social responsibility disclosure and overinvestment. Manuscript profile