The effectiveness of cognitive-behavior therapy aimed at helping patients with the acquisition of self-management skills to cope with pain, is thought to depend partly on the patients' willingness to adopt a self-management approach. Some patients may not believe that self-management will be helpful while others have decided to adopt it and others already apply the self-management skills in their daily lives. The present study explored the concept of 'Readiness to change' in a population of Dutch fibromyalgic patients. A self-report questionnaire was completed by 321 patients. Factor analysis revealed three scales, each assessing the characteristic of one stage of readiness to change, the Precontemplation, Contemplation and Action scale. Firstly, the reliabilities of these scales were 0.61, 0.86 and 0.61, respectively, and only the latter two scales correlated significantly (r=0.14). Secondly, the scales were validated using subscales from the Multidimensional Pain Inventory, beliefs on the credibility of the self-management approach and subscales from the Illness Perception Questionnaire. These subscales explained 5, 22 and 8% of the variance of the scores on the Precontemplation, Contemplation and the Action scales, respectively. Thirdly, on the basis of the three scale scores, over 80% of the fibromialgia patients could be classified into one of five potentially psychological relevant subgroups: Precontemplation, Contemplation, Preparation, Action and Relapse. The data suggest that improvements in operationalizations of the Precontemplation and Action dimensions of readiness to change are needed and that the theoretical foundation of readiness to change needs further development.