A model of cancer as a chronic illness is proposed as a new direction for quality of life research. In the cancer survivor adaptation (CSA) model, adjustment to cancer survivorship is a life-long process involving three interacting components. Personal context incorporates cancer survivorship and personal characteristics across biological, psychological, and social domains. The adaptation process involves a specific cognitive mechanism of change, where the ongoing appraisal of goals and world assumptions occur in the context of the cancer survivor's personal memories and sense of self. Finally, quality of life outcomes are viewed as multidimensional and personally weighted for importance, with expectations for both positive and negative physical, emotional, cognitive, and spiritual adjustments over time. Research and clinical implications are explored. © 2009 Wiley Periodicals, Inc. J Clin Psychol 65: 1–10, 2009.