This intervention study was performed to assess the effect of spirulina on lipid metabolism, antioxidant capacity, and immune function in elderly Koreans. The subjects were 6 male and 6 female people between the ages of 60 and 75, who were given spirulina supplements of 7.5 g/day for 24 weeks. Dietary intake, anthropometric measurements and biochemical assessment for plasma lipid levels, antioxidant status and immune function were measured before and throughout the intervention period. Before entering the study, the subjects were in relatively good health. Their nutrient intake was satisfactory, and anthropometric indices and plasma nutrient levels were within the normal range. Spirulina supplementation for 24 weeks did not affect dietary intake and anthropometric parameters. However, considerable changes were observed in blood lipid profiles, antioxidant capacity, and immune indices. The plasma concentrations of triglycerides, total- and LDL-cholesterol decreased from 4 weeks of the supplementation period. The antioxidant capacity improved, as shown in increasing TAS and decreasing TBARS after supplementation. Improved immune function was also observed as the PBL lymphocyte proliferation rate and plasma C3 levels increased. The above effects of spirulina supplementation did not differ between mild hypercholesterolemic (cholesterol $geq$ 200mg/d1) and normochole-sterolemic (cholesterol < 200 mg/dl) subjects. This study provided evidence that spirulina could be used as dietary supplementation in nutritionally vulnerable groups to improve nutritional and health status and to prevent chronic disease such as hyperlipidemia or oxidation-prone diseases. further studies in this area with various population groups are warranted.