The study was done to find out the causes that changes the fasting serum glucose level in postmenopausal women. This was descriptive type of cross sectional study carried out over a period of one year from July 2014 to June 2015 in the department of physiology, Mymensingh Medical College, Mymensingh. Women of reproductive age (25-45 years) and clinically diagnosed 100 menopausal women (45-70 years) were included for this study. Convenience type of sampling technique was used for selecting the study subjects. Measurement of fasting serum glucose was done by GOD-PAP method. Data were expressed as mean±SD and statistical significance of difference among the groups were calculated by unpaired student's 't' test. The mean±SD of serum glucose in menopausal women were significant at 1% level of probability than women of reproductive age. This study revealed that postmenopausal women showed higher levels of fasting serum glucose level. Fasting blood sugar level between the study & control group were 7.69±2.37 and 4.59±0.73 and the difference was statistically significant.