Adaptation is a task of case-based reasoning (CBR) that aims at modifying a case to solve a new problem. Now, belief revision deals also about modifications. This paper studies how some results about revision can be applied to formalize adaptation and, more widely, CBR. Revision operators based on distances are defined in formalisms frequently used in CBR and applied to define an adaptation operator that takes into account the domain knowledge and the adaptation knowledge. This approach to adaptation is shown to generalize some other approaches to adaptation, such as rule-based adaptation.