Background: Studies have reported that Cognitive Behavioural Therapy (CBT) and Graded Exercise Therapy (GET) are effective treatments for Chronic Fatigue Syndrome (CFS). Method: One hundred and seventy-one patients undertook a course of either CBT (n = 116) or GET (n = 55) and were assessed on a variety of self-report measures at pre- and posttreatment and follow-up. Aims: In this paper we present analyses on treatment outcomes for CBT and GET in routine clinical practice and evaluate whether changes on subscales of the Metacognitions Questionnaire-30 (MCQ-30) predict fatigue severity independently of changes in other covariates, and across the two treatment modalities. Results: Both CBT and GET were equally effective at decreasing fatigue, anxiety, and depression, and at increasing physical functioning. Changes on the subscales of the MCQ-30 were also found to have a significant effect on fatigue severity independently of changes in other covariates and across treatment modalities. Conclusion: The findings from the current study suggest that CFS treatment protocols for CBT and GET, based on those from the PACE trial, achieve similar to poorer outcomes in routine clinical practice as in a RCT.