We studied age-related changes in the concentrations in serum of ferritin, glycosylated ferritin, and non-glycosylated ferritin. The concentrations were determined in 95 healthy subjects: 39 men and 56 women, aged from 22 to 94 years. In the men, age correlated significantly with serum ferritin (r = 0.332, p < 0.05) and non-glycosylated serum ferritin (r = 0.628, p < 0.001) but not with glycosylated serum ferritin. In the women, age correlated significantly with serum ferritin (r = 0.456, p < 0.001), non-glycosylated serum ferritin (r = 0.439, p < 0.001), and glycosylated serum serum ferritin (r = 0.415, p < 0.01). The ratio of glycosylated serum ferritin to serum ferritin correlated negatively with age both in men and in women (men: r = -0.661, p < 0.001; women: r = -0.411, p < 0.01). Serum non-glycosylated ferritin levels were higher in older men. Both serum glycosylated ferritin and non-glycosylated ferritin levels were higher in older women, but this phenomenon was more pronounced with respect to the non-glycosylated form. These results suggest that hyperferritinemia in the elderly is mainly caused by an increase in the concentration of non-glycosylated ferritin, both in men and in women.