Regarding the influential role of top managers in the process of unlearning, the main question in this paper is "how top managers understand and approach unlearning" in their managerial activities. Toward this aim, based on several case studies with top managers who have recently been involved in the process of knowledge based changes, we realized that top managers are more apt to focus on technical and concrete types of knowledge such as knowledge which resides in systems and procedures. Moreover, among all different possible approaches toward unlearning, they mainly make sense of this it as a process of "pushing by new knowledge", and "abandoning old knowledge" that both of them are radical approaches toward unlearning. The main lesson drawn in this study is that researchers who interact with managers in their inquiry about unlearning must be aware about the natural orientations of top managers and how this might affect the validity of their field inquiry. Above all, the insights gained in this study shows that field study about unlearning based on the opinions of managers is easy to start with, as managers can make sense about this process easily, but is difficult to focus on, because managers easily shift from unlearning old knowledge to learning new knowledge in their thoughts.