Abstract Background: Anemia in infants and young children is characterized by reduced hemoglobin or red blood cell mass leading to impaired oxygen delivery; it is highly prevalent worldwide, especially in low‑resource settings. Clinically, affected children may show pallor, poor feeding, lethargy, delayed growth and neurocognitive development, and in severe cases tachycardia or heart failure. When anemia is severe or when a child requires anesthesia and surgery, optimization of oxygen‑carrying capacity is critical, and packed red blood cell (PRBC) transfusion may be necessary preoperatively to raise hemoglobin to a safe level for the perioperative period. This study aims to observe the rise in hemoglobin following preoperative packed red blood cell transfusion in infants and young children. Specifically, it will evaluate the hemoglobin response to a standard transfusion volume of 20 mL/kg, assess the influence of donor blood hematocrit on the magnitude of hemoglobin increase, and compare the measured post‑transfusion hemoglobin change with the estimated increase calculated from standard formulas. It will also compare the results with previously related studies. Methods: Study Design: Prospective observational study. Duration: August 2022 – June 2024. Participants: 322 infants and children (1–60 months) receiving preoperative PRBC transfusions of which 199 were male and 123 were females. Key Variables: - Pre-transfusion Hb (mean: 7.35 g/dL), hematocrit (mean: 22%). - Donor PRBC hematocrit (mean: 59.5%). - Transfusion duration: 4 hours (210 cases), 5 hours (58 cases), 6 hours (54 cases). - Post-transfusion Hb sampling: ~6 hours (60%), ~10 hours (10%). - Transfusion reactions: 8 cases (2.48%). Results: Hb Increase: -Actual change: Mean = 3.97 g/dL, Median = 4 g/dL. -Change as per Formula: Mean = 3.98 g/dL, Median = 3.91 g/dL. HCT Increase: -Actual change: Mean = 11.9 g/dL, Median = 12 g/dL. -Change as per Formula: Mean = 11.9 g/dL, Median = 11.74 g/dL. -Transfusion Reactions: 2.48% incidence, with no severe adverse events reported. Conclusions: Transfusions with higher Donor Hematocrit raised more Hb with the same volume dosage. Increase in Hb predicted through formula was closer to the actual value. Time of Post Transfusion Sampling did not affect the change in Hb significantly. Duration of Transfusion (4-6 hrs) did not have any serious adverse event.