Background: This study assessed the efficacy of a therapy combining a millimeter wave emitting wristband and coaching in improving the quality of life (QoL) of Fibromyalgia (FM) patients, compared to standard care. Methods: An open, randomized clinical trial enrolled 170 patients with FM (2016 American College of Rheumatology criteria, Fibromyalgia Impact Questionnaire score ≥ 39) from 8 French pain centers, and compared Immediate versus Delayed therapy. Therapy was provided at inclusion (D0) and month three (M3) in the Immediate and Delayed groups respectively. Therapy in the Immediate group stopped from month six (M6) to month nine (M9). Randomization was stratified by center, and FM severity, allocation ratio was 1:1. The primary outcome compared the proportion of patients with a Fibromyalgia Impact Questionnaire reduction ≥ 14% (minimal clinically important difference), from D0 to M3 in both groups. Pain (Visual Analogic Scale), sleep (Pittsburg sleep quality index), anxiety and depression (Hospital Anxiety and Depression Scale), fatigue (Multidimensional Fatigue Inventory Questionnaire), patients' and clinicians' impression of change (patient global impression of change & clinician global impression of change), physical activity (Global Physical Activity Questionnaire), generic QoL (euroqol, 5 dimensions, 5 levels), pharmacological and complementary treatment intakes, and healthcare requirements were measured at M3, M6, and M9. Results: At M3, 38/69 (55.1%) and 28/78 (35.9%) patients in the Immediate and Delayed groups respectively achieved the minimal clinically important difference ( P = .021). There were also significant improvements in sleep quality, pain, anxiety, depression, general and physical fatigue in the Immediate versus the Delayed group at M3. These benefits persisted at M6. Conclusion: Our results demonstrate that combined millimeter wave-based neuromodulation and coaching improve the QoL and other symptoms of patients with FM after 3 and 6 months.