The impact of companies’ social strategies, such as corporate social responsibility (CSR) and brand activism, on corporate advantages like economic and reputational gains has been well documented in the literature. However, research becomes scarcer regarding the broader impacts of these social strategies, namely the promotion of attitudes in favor of society and the environment on the part of company stakeholders. Furthermore, there is still little research on the variables that can mediate this impact, particularly at an identity and emotional level. To cover this gap, this article aims to study the impact of environmental brand activism on employee pro-environmental attitudes, and the possible mediating effects of identification with the organization and moral elevation by analyzing the brand activism of a Portuguese retail company. The results showed that environmental brand activism can directly affect the pro-environmental attitudes of employees and have also indirect impacts on the pro-environmental attitudes of this group of stakeholders, but only through the mediating role of identification with the organization, thus contributing to a better perception of the potential of brand activism to promote social change and sustainable development.