Introduction: Exogenous thyroid hormone usage for thyroid-stimulating hormone (TSH) suppression was found to be risky of bone loss for post-menopausal women (PW) after total thyroidectomy (TT).However, osteoporosis in euthyroid PW was not examined.We aimed to evaluate the frequency and severity of osteoporosis after TT in euthyroid PW.Methods: One hundred PW were included and were divided into two groups as the TT group (n=50) and the control group (n=50).The patients were in the post-menopausal period for at least 5 years, were euthyroid, and did not receive any drugs effective on bone metabolism.Age, length of post-menopausal period, and laboratory findings including TSH, triiodothyronine, thyroxine, serum calcium, serum phosphorus, serum magnesium, serum intact parathormone, serum alkaline phosphatase, 24-h urine calcium, and bone mineral density (BMD) of vertebra, femoral neck, trochanteric region, and Ward's triangle were analyzed and compared between two groups.BMD was expressed as T-score.Results: No significant difference was found between the two groups in terms of age, length of postmenopausal period, laboratory findings, and T-scores of L1, L2, and L4 vertebra.The T-scores of the L3 vertebra, femoral neck, trochanteric region, and Ward's triangle significantly differed between the groups (p=0.029,p=0.001, p=0.005, and p=0.000, respectively).Osteoporosis was observed in 50% of patients in the TT group, but this rate was only 16% in the control group and this difference was significant (p=0.001).Discussion and Conclusion: After TT, BMD decreases and the rate of osteoporosis increases in PW, even under replacement dose of exogenous thyroid hormone.