We proposed to assess serum antioxidant vitamins and magnesium (Mg) levels in patients with fibromyalgia (FM) in comparison to healthy controls. Additionally, the association between the serum antioxidant vitamins, magnesium levels, and clinical parameters in FM patients was also investigated. Forty female patients, aged between 30 and 50 years, were diagnosed with FM according to ACR-1990 criteria, and 40 healthy controls were included in the present study. Socio-demographic characteristics of participants, accompanying symptoms, and number of tender points (TP) of the patients were recorded. The intensity of pain was measured using the visual analogue scale (VAS). The functional status and depression levels were evaluated with Fibromyalgia Impact Questionnaire (FIQ) and Beck Depression Inventory (BDI), respectively. Serum vitamins A, C, and E and Mg levels were measured. There were no significant differences in the levels of vitamins A, C, and E and Mg between control subjects and patients with fibromyalgia (p > 0.05). In addition, no statistically significant correlations were found between mean levels of serum vitamins A, C, and E, and Mg and number of TP, scores of VAS, FIQ, and BDI in patients with FM (p > 0.05). According to the results of this study, it was asserted that other complex mechanism may play an important role in the pathophysiology of FM without plasma antioxidant vitamins and Mg levels.