Purpose– This paper aims to investigate the effect of corporate social responsibility (CSR) ratings on theex antecost of capital of more than 2,300 listed US companies in a panel from 2003 to 2010. It examines whether financial markets value continuous investment in CSR activities through higher market capitalization and lower cost of capital.Design/methodology/approach– The measure of the cost of capital reflects the perceived riskiness of individual companies expressed in the unobserved internal rate of return that investors expect to hold a risky asset. Based on descriptive portfolio estimations, panel and quantile regressions, the authors model the cost of equity capital as a function of CSR strengths and concerns obtained from the KLD-database and accounting controls.Findings– The authors show that firms' CSR strategies differ significantly across industry sectors. Customer-orientated companies such as telecommunications and automobile outperform asset-driven sectors such as real estate or chemical companies. Furthermore, the authors find a 10-bp positive effect for one standard deviation of firms' intensive allocation of resources in sustainable activities.Research limitations/implications– Since the authors are interested in the effect environmental, social and governance activities have on the firm's perceived market valuation rate, the authors apply the Fama-French model because of its efficiency in explaining realized returns, rather than incorporating analyst's long-term growth forecasts into the proxy for the equity premium.Practical implications– Managers of companies with low or intermediate CSR scores may consider the financial benefits of improving their social and environmental performance. A good starting point is usually to draw up a company-wide CSR agenda, possibly guided by a dedicated CSR task force, mapping out the potential costs and benefits of such measures. In addition, by improving their CSR ratings, a company may get access to additional resources, ranging from the growing ethical investment industry to employees for whom CSR performance matters when choosing an employer.Originality/value– The authors expand the existing literature by considering firm's CSR level to be in relation to the overall CSR performance and decompose firm's CSR agenda into strengths and concerns rather than counting the number of activities a firm is involved in. The applied methodology allows a better understanding of firm's CSR agenda and its implication for capital markets and investors on both long and short investment terms.