To study trends of anemia among middle-class children, we collected 6,162 hematocrit measurements from the medical records of 2,432 children, ages 9 months through 6 years, as seen at a private pediatric clinic during the past 18 years. A decline in prevalence of anemia was observed during that period. The overall age-adjusted rate of anemia decreased from 6.2% in 1969 to 1973, 5.8% in 1974 to 1977, 3.8% in 1978 to 1981, and 2.7% in 1982 to 1986. The decline was also observed when trends were determined for three age groups using a single hematocrit measurement per child. The 1982 to 1986 prevalences of anemia for various age groups among this middle-class pediatric population were relatively low: 2.8% among 9- to 23-month-old children, 2.4% among 24- to 47-month-old children, and 2.7% among 48- to 83-month-old children. Most of these recent cases of anemia were mild--most were only slightly less than the hematocrit values used to define anemia--and most did not show strong evidence of iron deficiency based on elevated levels of erythrocyte protoporphyrin. We conclude that iron deficiency is now mild and uncommon in these middle-class children. This improved nutritional status with regard to iron is probably related to increased intake of iron among infants and young children during the past two decades. These findings suggest that the recommended screening schedule for iron deficiency with hemoglobin or hematocrit measurements may need to be reassessed for well-defined populations of low-risk children.