OBJECTIVE: To determine the relationship of hemoglobin levels and anemia with age and health status in older adults. DESIGN: Survey. SETTING: Community. PARTICIPANTS AND METHODS: Hematologic tests were obtained from 3,946 adults aged greater than or equal to 71 years in three communities (East Boston, MA; Iowa and Washington counties, IA; and New Haven, CT). RESULTS: Hemoglobin level was inversely associated with age, although this was more pronounced in men than in women. The proportion anemic was equal for men and women aged 71-74 years (8.6%) and increased differentially with age, reaching 41% and 21% for men and women aged greater than or equal to 90 years, respectively. Hemoglobin and anemia were independently associated with age, race, body-mass index, smoking, cancer, hospitalization, renal insufficiency, and hypoalbuminemia. The adjusted relative odds of anemia for a 5-year increase in age was 1.5 (95% confidence interval [CI] 1.3-1.8) for men and 1.2 (95% CI 1.1-1.4) for women. CONCLUSIONS: Age is significantly associated with both hemoglobin levels and anemia, with a stronger effect in men compared with women, even after simultaneously adjusting for demographic characteristics and health status. The decline of hemoglobin and concomitant increased anemia with age is not necessarily a result of "normal aging" so the detection of anemia in an older person should prompt appropriate clinical attention.