Introduction: The aim of this study was to investigate whether the presence of fibromyalgia affects the bone mineral density (BMD) in hypothyroid patients. Methods: Our study consisted of three groups, including 30 patients with hypothyroidism and FMS, 30 patients with hy- pothyroidism, and 27 healthy volunteers. Lumbar vertebrae and left proximal femur BMD measurements of groups were performed by dual-energy X-ray absorptiometry. Groups were compared in terms of BMD. Results: Lumbar spinal total T score and lumbar spinal total BMD were significantly different between healthy volunteers and the other two groups. However, no significant difference was found between the groups in terms of age, gender, body mass index, smoking and alcohol use habits, erythrocyte sedimentation rate, C-reactive protein, thyroid-stimulating hormone, fT3, fT4, and 25-OH Vitamin D. Discussion and Conclusion: BMD was lower in patients with hypothyroidism and in patients with both fibromyalgia and hypothyroidism compared with healthy individuals. However, there was no difference in BMD between patients with both fibromyalgia and hypothyroidism and only with hypothyroidism.