We have determined Coenzyme Q 10 (CoQ 10 ) levels in salivary cells (SCs) and mononuclear blood cells (BMCs) from Fibromyalgia (FM), and we study the influence of oral CoQ 10 supplementation on cells levels and clinical symptoms.CoQ 10 was determined by high-performance liquid chromatography (HPLC). Ten patients were supplemented daily with 300mg of CoQ 10 during 3months.CoQ 10 were reduced in both cell models. Oral supplementation showed an improvement in clinical symptoms and restored levels.Patients with FM showed an important dysfunction in CoQ 10 levels and might benefit from oral supplementation.