Estimates of iron status in a random sample (218 men, 283 women) of the Northern Ireland population (aged 18-64 years) were obtained from blood measurements. Multiple criteria were used to determine Fe deficiency and body Fe stores were calculated as an index of Fe sufficiency. Three distinct groups with respect to Fe stores were identified on the basis of sex and menstrual status. Estimates of body Fe stores, mean (and SD), were 13.4 (SD 5.97), 5.3 (SD 6.09) and 8.5 (SD 6.72) mM for men, woman aged 18-44 years and women aged 45-64 years respectively. The prevalence of Fe-deficiency anaemia was low, ranging from 0.5% in men to 6.6% and 4.6% in the younger and older women respectively. The prevalence of Fe deficiency was low in men (1.4%) and older women (5.7%) rising to 11.0% in the younger group of women. The disproportionately elevated serum ferritin relative to transferrin saturation supported the suggestion that chronic inflammation might have influenced Fe status measurements in men and older women.