Evaluating IS/IT projects and deciding on their continuation has been hampered by the problem of equivocality. Equivocal situations hinder decision-makers to clearly recognise potential problems and implications of these decisions, as well as to decide the course of action in a purposeful fashion. However, little attention has been devoted to examine the causes of such situations. Extant literature was analysed and synthesised to identify typical characteristics of equivocal situations and uncover the potential causes of equivocality. We developed a framework based on this review and used it further to assist the investigation and to corroborate the causes of equivocality through expert interviews. In this paper, we investigated the causes of equivocality in practice by eliciting insights from different perspectives of decision-makers and their perceptions toward equivocal situations. We found that equivocal situations prevailed are much strongly related to the Challenges in project management, the Complexity in process and the Sophistication of technology within the Content of evaluation. Intriguingly, we found less solid relations with the Lack of standards and the Failure of evaluation methods as these two factors did not emerge as dominant causes during our discussions with the experts.