The prevalence of anemia in pregnant women in Indonesia according to Riskesdas (2018) is 48.9%. Anemia in pregnant women can cause bleeding, disability in infants, and can even cause abortion. To prevent complications due to anemia, pregnant women need to take blood builder supplements. The purpose of this study is to determine the effectiveness of blood builder supplementation to increase hemoglobin levels in pregnant women with anemia and to know the effect of anemia factors on increasing hemoglobin in pregnant women at Wirobrajan Primary Health Center. This research is a non-experimental research using an observational descriptive design. Data retrieval was carried out in July-September 2018 retrospectively by looking into the development data of pregnant women in Wirobrajan Primary Health Center with 61 data samples for effectiveness tests and 35 for analyzing the effect of anemia factors on increased hemoglobin. Data analysis was conducted by statistical test methods such as paired t-test and multiple linear regression. The results showed that there was significant differences between hemoglobin levels before and after blood builder supplement in patients with anemia (p <0.05). The results of the analysis of the effect of anemia factors on increasing hemoglobin levels showed no significant effect (p> 0.05). The conclusion of this study is that blood builder supplements effectively increased hemoglobin levels in pregnant women with anemia and there was no effect of age, parity and in between pregnancy period on increasing hemoglobin levels in pregnant women with anemia in Wirobrajan Primary Health Center.