Abstract-Business Process Reengineering (BPR) has become a popular managerial tool to deal with dramatic technological and business changes in today's competitive environment. BPR help organizations to throw away their old fashioned processes to achieve new heights of success. However, BPR implementation is a difficult task. Literature indicates that many organizations have failed to achieve the expected results. The present study attempts to throw more light to the subject. Through a comprehensive review of literature, critical success factors (CSF) that influence the success of BPR programs are identified. Then, using a DEMATEL methodology, these CSF and the causal relationships among them are analyzed. Results indicate that "top management commitment", "IT infrastructure", "training" and "adequate financial resources" are of critical importance in BPR implementation projects.