This paper proposes a new Green Government IT index to assess the environmentally responsible use of computers and other resources by the information technology departments of government institutions and nonprofit organizations. The methodology used in the paper relies on the established literature on index construction and the existing models for evaluating the environmental sustainability of information and communications technologies. The paper discusses the conceptual and theoretical foundations behind the new index and defines a set of verifiable, comparable, and transparent indicators for index construction. This framework allows for future index revisions as the green agenda evolves. The new index could be the first step before more resource-intensive assessments to inform an organization’s long-term environmentally sustainable strategy.