This study investigates the relationship between the implementation of a corporate social responsibility (CSR) strategy and the corporate financial performance of listed real estate investment companies. The sustainability of a company is measured using various self-constructed indices based on the Guidelines of the Global Reporting Initiative (GRI). Overall, a positive relationship can be established. An over-reporting of sustainability information dilutes this relationship. Furthermore, investors value initiatives which have a clear and coherent link to the enhancement of future value creation processes such as efforts to mitigate environmental impacts by reducing resource and energy consumption of buildings. A two-stage least squares regression framework is used to account for the problem of endogeneity.