BACKGROUND: Anemia cases in pregnant women in Indonesia are still high because pregnant women do not routinely take iron supplements or often referred as Tablet Tambah Darah because of the side effects it causes. An alternative to this problem is the intravenous administration of iron sucrose. AIM: The purpose of this study was to determine differences in ferritin and hemoglobin (Hb) levels before and after administration of iron sucrose injection to pregnant women in the second or third trimester at Araskabu Public Health Center, Deli Serdang. METHODS: This is an analytical study with a Quasi-Experimental Pre-Post Design for Second or Third Trimester Pregnant Women at Araskabu Public Health Center, Deli Serdang which was carried out in April 2022 by blood sampling and administration of iron sucrose injection intravenously, and then blood sampling was repeated 14 days after the injection in May 2022. The subjects in this study were 25 pregnant women aged 20–40 years who had antenatal care selected using the Consecutive Sampling technique. The difference in the mean of ferritin and Hb was analyzed using the paired t-test if the data are normally distributed and the Wilcoxon test if the data are not normally distributed. The results were significant if p < 0.001. The Mann–Whitney and Kruskal–Wallis tests were used to examine the difference between two or more sample groups. The results of the analysis were significant if p < 0.050. RESULTS: The mean ferritin level before administration of iron sucrose injection to pregnant women in this study was 18.97 ± 8.284 g/L and the mean ferritin level after iron sucrose injection was 98.95 ± 18.878 g/L. The mean increase in ferritin levels after injection of iron sucrose was 79.97 ± 19.77 g/L. The mean Hb level before administration of iron sucrose injection to pregnant women in this study was 10.13 ± 0.386 g/dL and the mean Hb level after administration was 12.01 ± 0.723 g/dL. The mean increase in Hb levels after injection of iron sucrose was 1.88 ± 0.68 g/dL. CONCLUSIONS: Iron sucrose injection can significantly increase ferritin and Hb levels.