Iron deficiency anemia is prevalent in Indonesia (38-71%), particularly among the pregnant women, despite of the large scale anemia control program launched by the government since 1970’s. The anemia control program included iron supplementation, nutrition education, food fortification, and parasite control. The results of the iron supplementation program is not yet as expected. Low compliance in taking iron pills was a reason suspected as the cause of the unexpected results. Several methods had been studied to increase the number of iron pills intake. However, the synthesis of hemoglobin is not only dependenton iron from the pills but also requires other blood forming nutrients from the diets. A two phase descriptive study was conducted to study the factors influencing the iron status of pregnant women in the second trimester participating in the National Anemia Control program in three subdistricts of Bogor district. The first phase was conducted for four weeks to obtain informations on hemoglobin and serum ferritin, socioeconomic condition, daily diet and nutrients intake, knowledge on anemia, on iron pills,and on Puskesmas Services, health behaviour, ante natal care attendance, and number of iron pills intake. The number of pregnant women joining the study was 456, they attended the ante natal care clinic of the Puskesmas of three subdistricts of the district of Bogor. The prevalence of anemia (Hb