Background: This study aimed to investigate the changes of serum zinc in term neonates who need major operation.
Materials and Methods: In this study, 59 neonates who need major operation were studied. All patients underwent major surgical with high stress. The metabolic response to surgery was studied by measuring the serum zinc before and after surgery (24 hours and at discharge time postoperatively). The "repeated measure" analysis was used to test changes of plasma values of zinc over time. 
Results: The plasma values of zinc was 89.78±14.50 µg/dl after surgery, 74.95±15.86 µg/dl in 24 hours after surgery and 93.78±14.53 µg/dl at discharge. The plasma values of zinc decreased immediately after surgery that this decline continued until the first 24 hours of operation. Serum zinc concentration decreased significantly at 24 hours at discharge. No significant differences were found between the two sex groups.
Conclusion: According to the results of this study, zinc levels in term neonates who need major operation were decreased temporary but later returned to normal. It seems that in these patients there is no need for supplementation of zinc during two weeks after operation.