The authors declare that they have no conflict of interest.All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent was obtained from all individual participants included in the study. 2 Abstract PurposeAcceptance and flexible goal adjustment are believed to be protective factors in chronic illness whereas tenacious goal pursuit is considered maladaptive. The present study aimed to investigate the role of these factors in quality of life of patients with Multiple Sclerosis (MS). MethodsA sample of 117 patients with MS was recruited. They completed questionnaires measuring quality of life (physical functioning, psychological functioning, psychological distress), acceptance, flexible goal adjustment, and tenacious goal pursuit. ResultsAcceptance significantly accounted for variance in all three indexes of quality of life, beyond the effects of demographic and illness characteristics. The role of goal regulation style was less clear. Flexible goal adjustment significantly accounted for psychological wellbeing only. Surprisingly, tenacious goal pursuit predicted better psychological functioning and less psychological distress. No support was found for the hypothesis that acceptance and flexible goal adjustment would moderate the relation between illness severity and quality of life. ConclusionsThe findings suggest the potential importance of acceptance in understanding MS patients' quality of life, although its hypothesized protective function could not be confirmed. Further conceptual work on acceptance and goal regulation style is needed, as well as prospective work investigating their causal status.