Purpose: The main objective of this study was to determine the extent to which physical and cognitive-affective factors are associated with fibromyalgia (FM) fatigue. Method: A quantitative descriptive design using correlation techniques and multiple regression analysis. The participants consisted of 302 members of the National Fibromyalgia & Chronic Pain Association. Results: The results indicated all of the predictor variables were significantly related to FM fatigue; however, in the regression model, only pain intensity and sleep quality uniquely contributed to fatigue. Conclusions: These findings suggest that FM fatigue treatment should focus on physical factors before addressing other symptoms. The implications for rehabilitation counselors in developing evidence-based approaches to fatigue management are discussed.