Successful implementation of an executive information system (EIS) is not an easy job for most of organizations. Out of many factors to be considered, the success or failure of an EIS ultimately depends on how well the implementation process is managed in terms of both technology and users. This article with regarding to senior managers’ information needs to make strategic decisions, was about to recognize critical success factors in implementing EIS in the Iranian organizations. Statistical Population in this research included managers and experts in Petroleum Equipment Industries Corporation (PEIC) and its subordinates. A questionnaire was developed by researchers for gathering data from sample population. Research findings based on factor analysis was indicative of following critical success factors for implementation of EIS: 1) Development of an appropriate conceptual model; 2) a participative approach in design and development; 3) a relevant technology; 4) role of IT Department; 5) project management of EIS; 6) supportive role of senior management; and 7) software capabilities. The model explained 59 percent of the variance in successful implementation of EIS. Therefore, it should be bear in mind that there are others CSFs which were not recognized in this research.