One of the most important reasons why organizational transformations fail is the existence of a conflict between what the organization wants to do and who it really is. This conflict can be understood by means of the notion of mental model, which corresponds to the way the organization sees its environment and itself. With this perspective, transformation is about changing the organization’s individual and collective mental models. While this is difficult in itself, it is even more so when the current model, which must evolve, is perceived as valid, because this leads to a conflict between the existing and the desired model. Surfacing this conflict and explicitly addressing it is the key to successful organizational transformation.