The energy sector has gone through changes, it has been liberalised, sustainable development has added a new dimension, and companies operating in it are increasingly expected to demonstrate environmental responsibility. In this thesis how the concepts of sustainable development and environmental responsibility are treated rhetorically in the corporate environmental communication of three Swedish electricity companies is analysed. The corporate environmental communication is viewed as a part of the companies’ public relations strategies. Rhetoric is used by companies to establish and maintain good relations with their stakeholders. If the premise that rhetoric has the ability to do something through its creation and promotion of meaning is accepted, the corporate rhetor plays a part in the definition and shaping of societal values, standards of business and public policy. It is argued that the electricity companies all present themselves as being responsible and sustainable though these claims contribute little to the definition of what environmental responsibility means and what sustainable electricity production is. The rhetoric used is a means for gaining legitimacy and competitive advantages to go on with business as usual. The electricity companies’ very similar rhetorical strategies pose an obstacle for stakeholders trying to evaluate the environmental performance of the companies.