Objective: This study evaluated the success of implementing cognitive behavioral therapy (CBT) for chronic fatigue syndrome (CFS) in a representative clinical practice setting and compared the patient outcomes with those of previously published randomized controlled trials (RCTs) of CBT for CFS. Method: The implementation interventions were the following: spreading information about the new treatment setting to general practitioners and CFS patients; training mental health center (MHC) therapists in CBT for CFS; and organizing changes in the MHC patient workflow. Patient outcomes were documented with validated self-report measures of fatigue and physical functioning before and after treatment. The comparison of the treatment results with RCT results was done following the benchmark strategy. Results: One-hundred forty-three CFS patients were referred to the MHC, of whom 112 started treatment. The implementation was largely successful, but a weak point was the fact that 32% of all referred patients dropped out shortly after or even before starting treatment. Treatment effect sizes were in the range of those found in the benchmark studies. Conclusions: CBT for CFS can successfully be implemented in an MHC. Treatment results were acceptable, but the relatively large early dropout of patients needs attention.