Organizations increasingly recognize that environmental sustainability is an urgent problem. Green information systems (Green IS) initiatives can assist organizations in reaching their environmental goals by providing the ability to reduce the environmental impacts of information technology (IT) manufacturing, operations and disposal; facilitate transparency and enhance the efficiency of organizational resources and business processes; and foster eco‐products through technological innovation. However, the nature and type of benefits such initiatives can accrue remain poorly understood, and accordingly, IT executives struggle to integrate environmental aspects in the corporate strategy and to launch Green IS initiatives. This paper clarifies the mechanisms that link organizational beliefs about environmental sustainability to Green IT and Green IS actions undertaken, and the organizational benefits that accrue from these actions. Using data from a global survey of 118 senior‐level IT executives, we find that Green IS strategies mediate the relationship between environmental orientation and the implementation of Green IT practices and Green IS practices, which in turn lead to organizational benefits in the form of cost reductions, corporate reputation enhancement and Green innovation capabilities. Our findings have implications for the potential of IS to enable organizations' environmental sustainability and also for the differentiation of Green IT and Green IS practices. © 2017 John Wiley & Sons Ltd