The study was conducted to evaluate the diagnostic value of OPG & crosslaps in osteoporosis, and to study a possible protective role of leptin and obesity against it.There was a significant positive correlation between leptin and bone mineral density mean T score at different sites of the body (r=0.553 p<0.01), and this correlation was still significant after nullification of BMI and age (r=0.46 p<0.01). There was also a significant negative correlation between mean T score & bone markers (OPG: r-0.797, crosslaps:r-0.770, total ALP:r=0.676, bone ALP:r=0.799, at p< 0.001).