Iron status including S-ferritin and haemoglobin (Hb) was assessed in a population survey comprising 1433 Danish males in age cohorts of 30, 40, 50 and 60 years. There was no significant difference in S-ferritin levels between the age groups. In the entire series, median S-ferritin was 126 μg 1^-1, 5-95% tile 31-378 μg 1^-1, range 5-3600 μg 1^-1; 1.2% had values <15 μg 1^-1 (i.e. depleted iron stores), 3.7% values from 15-30 μg 1^-1 (i.e. small iron stores), and 95.1% values 30 μg 1^-1 (i.e. replete iron stores); 73.8% had values from 61-300 μg l^-1, and 9.5% values > 300 μg 1^-1. Blood donors had lower S-ferritin than non-donors and a higher frequency of depleted iron stores (p<0.0001). Hb values showed no age variation; median values was 155 g 1^-1 (9.6 mmol 1^-1), 5-95% tile 137-171 g 1^-1 (8.5-10.6 mmol 1^-1). Hb values <129 g 1^-1 (8.0 mmol 1^-1) were observed in 1.7%, and values <121 g 1^-1 (7.5 mmol 1^-1) in 0.8%. Males with S-ferritin <15 μg 1^-1(n=17) had lower Hb, median 148 g 1^-1 (9.2 mmol 1^-1), than those with S-ferritin =15 μg 1^-1, median 155 g 1^-1 (9.6 mmol 1^-1) (p<0.05). Iron deficiency anaemia (S-ferritin <15 μg l^_l and Hb<129 g 1^-1) was seen in 0.14% of the males. There was no relation between S-ferritin and nutritional iron intake. The results indicate that iron intake and absorption was sufficient in 99.9% of the males to meet the requirements for erythropoiesis, and sufficient in 95% to establish appreciable iron reserves.