Strategic decision makers typically use a wide range of communication and information media in complex, uncertain and often ambiguous or politically charged organizational contexts. However, little help is available in ensuring that their information behaviour is efficient and effective. This study evaluates the use of information systems (IS) as communication media in strategic decision-making processes (SDMPs), focusing on strategic information processing, and how context affects its performance. The analysed strategic decisions (n = 113) were taken in the time period between 2000 and 2008 in large Western organisations. The aim of this investigation was to look at the link between the use of IS during the decision-making process and the performance of the SDMP, taking into account internal and external contextual factors. Using existing information processing theory and research on the SDMP as a theoretical basis, hypotheses were developed and environmental contingencies and political information behaviour were selected as moderating effects on the relationship of IS use and the performance of strategic decisions. A survey and complementary semi-structured interviews were conducted, which studied particular strategic decisions through quantitative and qualitative methods. Results provide support for a number of the study¿s hypotheses; however, several interesting findings regarding contextual factors, such as information anarchy and environmental munificence/hostility, do not support the hypotheses. Implications for theory and practice concerning information behaviour and its context are discussed.