Objective: To compare the nutritional status in CHD children before and after surgery, to identify the association between acute malnutrition and epidemiological and nutritional characteristics. Methods: prospective, descriptive and case-series analysis. Subjects were consecutive patients with CHD aged 0-24 months admitted to Cardiology ward, The Children's Hospital No1 for cardiac surgery from May-Sept 2013. Anthropometry, laboratory tests for nutrition and immune were per formed at admission and 1 month after surgery. STATA 8.0 was used for data analyzing. Results: Nutritional status of30 patients was improved after surgery (p0.05) but prevalence of malnutrition was still high: underweight, stunting, and wasting was 73.3 percent, 46.7 percent, 60 percent, respectively. There was no association between wasting and epidemiological and nutritional factors(p 0.05). Onethird of them (33.3 percent) were anemic, 43.3 percent of them had low vitamin D (70nmol/L). The percentage of patients with decreased IgA and IgG were 90 percent (70mg/dl) and 70 percent (700mg/dl), respectively. There were no significant improvement of laboratory tests after surgery, except IgA, IgG levels (p0.05). Conclusion: Nutritional status was improved after cardiac surgery but prevalence of malnutrition still high. Children with CHD had micronutrients deficiencies and altered immune response.