This study was conducted to examine the relation between iron status and neurobehavioral development in premature infants. Infants born before 34 weeks postmenstrual age and who were medically stable were studied. Anemia was defined as hemoglobin < or =10 g/Dl and low iron stores as a serum ferritin concentration < or =75 microg/l. The infants were classified as anemic with low ferritin (Group 1; n=18), anemic with normal ferritin (Group 2; n=14), and nonanemic with normal ferritin (Group 3; n=21). A total of 18 reflexes were behaviorally evaluated at 37 weeks postmenstrual age and "reflex scores" were compared between the groups. Higher scores reflect a greater percentage of abnormal reflexes. Infants in group 1 (anemia/low ferritin) had a significantly higher reflex score (51.45+/-18.32%) than infants in Group 3 (38.32+/-17.75%). Group 2 had an intermediate score (45.40+/-21.70%), but not different from the other two groups. These data indicate that low iron status, both measured by anemia and ferritin levels, is related to poorer neurobehavioral status in premature infants.