In recent decades, the debate about the strategic potential of corporate social responsibility (CSR) and the existence of a possible relationship between CSR and competitiveness has become increasingly relevant. However, the literature has not analysed in detail why this influence occurs and what the key elements that determine increasing competitiveness are. This study analyses the roles of innovation and investment in the ways in which CSR influences competitiveness. The results from an empirical study of 236 companies show no direct influence of CSR on competitiveness, but innovation and investment are shown to affect CSR's influence on competitiveness indirectly and significantly. These results demonstrate a total mediation effect of innovation and investment on CSR's influence on competitiveness. The theoretical and practical implications of this study are discussed together with its limitations and potential for future research. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment