Background: Unforeseen aberrations in the hormonal status during the early postmenopausal period are responsible for several complications including osteoporosis. Thyroid Stimulating Hormone (TSH) receptors are isolated from various tissues including the bone. A low serum TSH level is known to stimulate osteoclastic activity in bone and accelerate bone resorption. Urinary calcium/creatinine (UCa/Cr) excretion ratio could be an indirect and an early indicator of loss of Bone Mineral Density (BMD). With this background, this study was planned to explore the association of serum TSH levels with the UCa/Cr excretion ratio.Methods: Forty eight women in the postmenopausal age group, with their menopausal age not more than seven years of duration were included in this study. Based on their TSH values, these subjects were divided into two groups A (TSH<0.5 mIU/L) and B (TSH>0.5mIU/L). Urinary calcium, UCa/Cr excretion ratio, serum phosphorous, calcium and calcium phosphorous multiplication products were estimated and compared between the two groups.Results: Twenty two (46%) women were biochemically asymptomatic hyperthyroid cases and Twenty six (54%) were euthyroid. This study documents high UCa/Cr in Group A compared to that of Group B (p<0.05). We also observed significant negative correlation of TSH with UCa/Cr excretion ratio (p=0.041, r = -0.43). Conclusion:Low serum TSH levels were associated with increased UCa/Cr excretion ratio in postmenopausal women of South Indian population.NiraNjaN G, amrutha P V, SriNiVaSaN a r, rameSh r, SathiShbabu m, Sathiya r