Executive Information Systems (EIS) are designed to enhance the managerial roles of executives, including other senior managers, in organizations. Despite reported growth in the popularity of EIS, there are reports of low usage of these systems that, in part, contributes to their failures in organizations. The majority of prior EIS research has focused on documenting the features, benefits, development methodologies, and implementation of the systems. However, very few research studies address the problem of low EIS usage from behavioural point of the user. This chapter reports on a research on the use of EIS in organizational settings. The primary focus of the research is to investigate factors that explain users’ behaviour towards using EIS. It is also aimed at identifying the relative importance of those factors that determine the use of EIS. The research model is based on Triandis’ theoretical framework, a model from organizational behaviour. The research model is used to hypothesis that EIS use (behaviour) is determined by EIS experience and ability to use EIS (habits); subjective norms, roles, values and social situations (social factors); perceived usefulness of EIS (consequences); user satisfaction with EIS information, system, support, and plan (affect); and EIS development processes, management processes and organisational environment (facilitating conditions). Field data obtained by survey questionnaire from CEOs, CFOs and one other executive from 255 organisations using EIS in Australia were used to test and confirm the appropriateness of the behavioural model through correlation and regression analyses. The results of the study have some implications for research and practice.