Introduction: The aim of this study was to determine the effects of diabetes mellitus (DM) on bone mineral density (BMD)by comparing the BMD values of healthy controls with those of patients with type 1 and type 2 DM.Methods: A total of 41 patients (23 men, 18 women) with type 1 DM aged 25 to 50 years and 40 (21 men, 19 women) sexandage-matched non-diabetic controls, as well as 91 patients (26 men, 65 women) with type 2 DM aged 40 to 55 years and60 (17 men, 43 women) sex- and age-matched non-diabetic controls were included in the study. The BMD values of thefingers of the non-dominant hand were measured using an Alara Metriscan bone densitometer (Alara, Inc., Hayward, CA,USA). Patient height, weight, duration of DM, glycated hemoglobin (HbA1c) value, and smoking and exercise history datawere recorded. The level of statistical significance was established at p<0.05.Results: The mean BMD value of the patients with type 1 DM and the matched healthy controls was 58.29±5.42 g/cm2 and59.31±4.14 g/cm2, respectively, while the mean BMD value in the type 2 DM group and the matched healthy controls was55.85±6.34 g/cm2 and 55.93±7.40 g/cm2, respectively. There was no statistically significant difference between the BMD valueof either the type 1 DM or the type 2 DM group and the healthy controls. There was a significant negative correlation betweenthe HbA1c level and T-score and the BMD value in the type 1 DM group, but no significant relationship was found in the type2 DM group.Discussion and Conclusion: There was no significant difference between the BMD value of the patients with either type 1or type 2 DM and the healthy controls.