The purpose of this study was to compare iron related indices in patients with iron deficiency anemia and chronic causative diseases between geriatric older than 65 years and adult, nongeriatric younger than 65 years groups. Iron deficiency anemia (IDA) cases with chronic disorders from Youngdong Severance hospital from June, 1991 to April, 1994, older than 65 years (17 cases), and younger than 65 years (29 cases) were analysed with iron related indices. Mean hemoglobin was 7.8 +/- 2.2 g/dl in geriatric IDA and 8.0 +/- 1.8 g/dl in adult IDA without significant difference. RDW value was 19.5 +/- 2.6 in geriatric IDA and 18.4 +/- 3.2 in adult IDA with no significant difference. Serum iron and transferrin saturation between geriatric IDA were 22.7 +/- 12.3 ug/dl, 6.7 +/- 4.1% and 28.6 +/- 16.6 ug/dl, 7.1 +/- 4.4% in adult IDA with no significant difference, but TIBC was significantly lower (P = 0.011) in geriatric IDA than in adult IDA patients (357.2 +/- 83.2, 413.6 +/- 54.0 ug/dl). In normal elderly people, serum ferritin was 152.5 +/- 95.4 ng/ml in male and 111.1 +/- 54.1 ng/ml in female with range 19.8 approximately 367.7 ng/ml in male and 11.7 approximately 238.7 ng/ml in female and was higher than that of normal adult in both sexes (147.0 +/- 108.0, 35.3 +/- 20.5 ng/ml) (P = 0.045). Serum ferritin in geriatric IDA was 13.8 +/- 11.8 ng/ml and 5.7 +/- 4.0 ng/ml in adult IDA with significant difference(P = 0.001). The Upper margin for geriatric IDA was 37 ng/ml with 95% confidence interval. In the diagnosis of geriatric IDA with causative diseases, we should consider that TIBC does not increase and the upper margin for serum ferritin is suggested to increases up to 37 ng/ml.