It has been well documented that independently both exercise and niacin positively alter blood lipids and lipoproteins; however, these interventions have not been studied in postmenopausal women. Purpose. This study examined the independent and combined effects of niacin and a single bout of exercise on the blood lipid and lipoprotein profiles in postmenopausal women. Methods. Eighteen sedentary, postmenopausal women (40–80 years old), were recruited (mean ± SD; age = 57 ± 6 yrs; height = 161.3 ± 6.7 cm; weight = 75.8 ± 13.9 kg; % body fat = 46.2 ± 6.6%). The without-niacin (WON) condition was first assigned followed by the with-niacin (WN) condition. The WN condition consisted of ingesting 1,000 mg/day of extended-release niacin for 4 weeks. Rest (R) and exercise (E) trials were randomly assigned within each WON or WN condition. During the E trial treadmill exercise was performed at 60% HRR until 400 kcal were expended. Fasting blood samples were collected immediately before (0 hr) and at 24 and 48 hr post exercise (or rest). All data were reported as mean ± SD. The changes in TC, TG LDL-C, HDL-C, HDL₂-C, HDL ₃-C, and TC to HDL-C ratio were analyzed using a 2 (WON and WN) × 2 (Rest and Exercise) × 3 (0, 24, and 48 hr) ANOVA with repeated measures. The Bonferroni post-hoc test was applied and the statistical significance was set at p < .05. Results. The concentrations of TC, LDL-C, and TG were not altered in reponses to exercise or niacin. However, the niacin treatment without the exercise intervention significantly ( p < .05) increased HDL-C (5.4 mg/dl or 12.4%) and HDL₂-C (3.6 mg/dl or 33.3%) from baseline (43.5 ± 1.7 and 10.8 ± 1.2 mg/dl, respectively). The HDL₃-C concentration at EWN-48 hr (35.1 ± 1.1 mg/dl) was significantly (p < .05) higher as compared to EWN-0 hr (33.7 ± 1.0 mg/dl) and EWON-48 hr (32.7 ± 1.3 mg/dl). Conclusion. The niacin treatment (1,000 mg/day) for 4 weeks favorably altered HDL-C, predominantly HDL₂-C. However, HDL₃-C increased only when a single bout of exercise was perfomed during the niacin treatment.