Background: Leptin balances body weight, but its role in the negative energy imbalance is unclear. Increased energy expenditure reduces newborn with cyanotic congenital heart disease development. Aim and objectives: The researchers wanted to see how much leptin was in the blood of kid's congenital heart disease (CHD), both cyanotic and acyanotic, as well as to look into its involvement in their growth. Subjects and methods: In this study, 38 Egyptian patients with congenital heart disease participated (18 with acyanotic CHD and 20 with cyanotic CHD), as well as (20) seemingly normal youngsters of same age, gender, and socioeconomic level as a control group. Results: A total sample of 58 withmean age 7.7± 4.2, 8.3± 4.1 and 9.1± 3.8 in cyanotic, acyanotic and control groups. Mean of serum leptin among control group was 3.7± 1.3. The mean of serum ghrelin among acyanotic group was 5.3± 1.8. There was positive correlation between age, BMI, O₂ saturation, MAC, and serum leptin. But there was negative correlation between age, BMI, O₂ saturation, mid upper arm circumference (MAC), and serum ghrelin. There was negative moderate statistically significant correlation between serum leptin and serum ghrelin. Conclusion: Elevated leptin and reduced gherlin levels were found in children with congenital heart diseases, whether cyanotic or acyanotic, suggesting a role for both hormones in regulation of nutrient intake, energy balance and maintenance of body weight in those children.