ObjectiveTo determine the prevalence of acute malnutrition and low biological markers in children with congenital heart disease (CHD) before and after corrective surgery, Children's Hospital 1, Ho Chi Minh City, Vietnam.MethodsProspective observational study of 30 consecutive children <24 month old with CHD admitted for corrective surgery, 5‐9/2013. Data included age, cardiac diagnosis, length of hospital stay, among others. Weight, height, serum markers of nutrition, inflammation and immunity were measured before and 1m after surgery. Anthro‐software (WHO) and STATA 12 were used.ResultsThe sample consisted of 30(40% male) patients aged 8.5±4.0m. The interval between diagnosis and surgery was 6.7±3.8m and hospital length of stay 27±14d. A total of 24(80%) children were wasted before and 18(60%) 1m after surgery (P<0.001). At baseline, 14(47%) had anemia, 8(27%) low retinol, 7(23%) low thiamine, and 20(67%) low IGG, among others. There was a significant improvement in the prevalence of low IGG (p=0.018) but not of other biological markers (p>0.05) after surgery.ConclusionEarlier surgery and comprehensive nutrition intervention might further improve these results. (Support: Abbott Fund)