Very low birth weight (VLBW) infants usually receive packed red blood cell unit (pRBC) transfusions. Heavy metal transfer via pRBCs is not widely discussed before. This study aimed to determine pre-/post-transfusion erythrocyte lead and mercury levels in infants and to correlate these levels to heavy metal concentrations in pRBCs. VLBW infants (n = 80), needing pRBC transfusion for the first time, were enrolled. Erythrocyte heavy metal levels were determined in pre-/post-transfusion blood samples and also in pRBC units. Mean lead and mercury levels in the pRBCs were found to be 16.3 ± 10.8 and 3.75 ± 3.23 μg/L, respectively. Of the infants, 69.7% received lead above reference dose. Erythrocyte lead levels increased significantly after transfusions (10.6 ± 10.3 vs. 13 ± 8.5, p < 0.05) with significant correlated to amount of lead within pRBCs (r = 0.28). Mean pre-/post-transfusion erythrocyte mercury levels were 3.28 ± 3.08 and 3.5 ± 2.83 μg/L, respectively (p > 0.05). There was a significant correlation between mean difference of mercury levels after transfusion and amount of mercury delivered by pRBCs (r = 0.28). Infants can be subject to high levels of lead and mercury through pRBC transfusions.