OBJECTIVE: In this randomized noninferiority study, the effectiveness and efficiency of stepped care for chronic fatigue syndrome (CFS) was compared to care as usual. Stepped care was formed by guided self-instruction, followed by cognitive behavior therapy (CBT) if the patient desired it. Care as usual encompassed CBT after a waiting period. METHOD: A total of 171 CFS patients were randomly allocated to stepped care or care as usual. Patients in both conditions were assessed 3 times: at baseline, after guided self-instruction or the waiting period, and after CBT. The primary outcome variables were fatigue severity (Checklist Individual Strength) and disabilities (Sickness Impact Profile and Medical Outcomes Survey Short Form-36). RESULTS: An intention to treat analysis showed that stepped care (N = 84) for CFS is noninferior to care as usual (N = 85). Both conditions were equivalent in reducing fatigue severity, reducing disabilities, and increasing physical functioning. The treatment results of both conditions were in accordance with those of previous randomized controlled trials testing the effectiveness of CBT for CFS. The total therapist time needed to treat a patient was significantly less in the stepped care condition. CONCLUSIONS: Stepped care is as effective as CBT and is more time efficient for the therapist.