This paper investigates the total and single impact of the dimensions of corporate social responsibility on each of (cost of equity, firm value) of the company using a sample of 70 Egyptian listed companies from different sectors during the period from (2012-2018). Dimensions of corporate social responsibility measured by an unweighted disclosure index consisting of 31 items and divided into 4 dimensions of social responsibility (employees, society, environment, customers).Cost of equity was measured using (Easton, 2004) model not (CAPM) due to its lack of suitability for the Egyptian environment due to its assumption of the efficiency of the market, and firm value was measured using the (Tobin's Q) scale, where the market prices of stocks are relied upon, which represents the investors ’evaluation of the company, and it is one of the best operational measurements for profitability and financial performance of companies. The researcher used one lag period time and three lag periods in the empirical study. The results provide evidence that there was no total or single significant impact of the dimensions of corporate social responsibility on both (cost of equity, firm value) using one lag period time, While there is a negative and significant impact of the dimensions of csr on the cost of equity, and there is also a positive and significant impact of the dimensions of corporate social csr on firm value, using three lag periods except customers dimension. The impact of csr dimensions on cost of equity and firm value depends mainly on lag period time that companies need to reflect the impact of this type of disclosure on the shares of these companies under the awareness of investors of the importance of this type of disclosure and that profit is not the only standard when Making investment decisions, but social responsibility dimensions must be considered. The main responsibility of the company is the social responsibility if it wants to stay and continue for the long term.