This study analyses the impact of investment in climate change mitigation innovations and technologies on companies, both from a financial and reputational viewpoint, as well as in terms of their environmental performance. We also investigate the moderating effect of institutional investors on the relationship between climate change mitigation investments and firm performance, considering their presence in shareholdings and their typology. We argue that the time horizon and objectives of their investments determine the approach to the integration of environmental criteria in the companies in which they invest. The results obtained for an international sample of 38,666 observations for the period 2010–2020, indicate that investment in climate-change mitigation technologies shows an increasing evolution, focusing especially on clean technologies and, to a lesser extent, on green building. The presence of shareholding by institutional investors with a long-term time horizon and strategic objectives enhances the impact of these projects on the company's image, market value, and profitability. At the environmental level, their effects are particularly associated with the responsible management of resources, and has a limited effect on emissions. The results are robust to different methodological specifications, validating the theoretical and practical implications of this research.