Objectives: Cardiovascular autonomic nerve dysfunctions often develop in postmenopausal women that commonly affect sympathetic nerve function. The objectives of this study were to observe the sympathetic nerve function status and their relationships with serum estrogen level in postmenopausal women. Methods: This cross sectional study was carried out in the Department of Physiology of BSM Medical University, Bangladesh from 1^st January to 31^st December 2007. For this purpose 30 postmenopausal women (group A) with age ranged from 45 to 60 yrs and 30 premenopausal women (group B) with age ranged from 20 to 30 yrs were taken. Premenopausal women were studied during follicular phase of menstrual cycle. Resting blood pressure and heart rate were measured in both the groups. Two simple non-invasive cardiovascular autonomic nerve function tests were done and serum estrogen and progesterone levels were measured in both the groups. Correlations of sympathetic nerve function parameters with hormone levels were also observed. Again, regression analysis was done to observe the contribution of serum progesterone, age and BMI (body mass index) on sympathetic nerve function of postmenopausal women. Results: Mean value of estrogen was significantly (p<0.001) lower in group B than that of group A. Fall in systolic blood pressure one minute after standing was significantly (p<0.001) higher in group B than group A. Again, rise in diastolic blood pressure after sustained handgrip was significantly (p<0.001) lower in group B than group A. In addition, regression analysis revealed significant association of sympathetic nerve function with age in postmenopausal women. Conclusion: These data supports that sympathetic nerve function decreases in postmenopausal women, which is associated with age of this group of women. Key words: Postmenopausal women, sympathetic nerve functions, estrogen, and age.