Congenital heart disease (CHD) occurs in approximately 9 per 1,000 live births and can impair growth due to chronic hemodynamic burden, feeding difficulties, and increased energy demands. This study aimed to describe the nutritional status of children with acyanotic CHD and assess its relationship with diagnosis and defect size. A cross-sectional analytical study was conducted involving 34 children with patent ductus arteriosus (PDA) or ventricular septal defect (VSD) scheduled for transcatheter closure. Nutritional status was determined using anthropometric measurements, while defect size was assessed by 2D echocardiography. Associations were analyzed using Spearman correlation and Kruskal-Wallis tests. Of the 34 subjects, 58.8% (n=20) had good nutritional status, 29.4% (n=10) were undernourished, and 11.8% (n=4) had severe malnutrition. Malnutrition was slightly more common in VSD (50.0%) than PDA (37.5%). Defect size ranged from 2.0–7.0 mm, with a median of 5.0 mm, and most defects were classified as small to moderate. Median defect sizes were 5.0 mm in both the good nutritional status and undernutrition groups and 4.5 mm in the severe malnutrition group, with no significant difference (p=0.549). Nutritional status was also not significantly correlated with absolute defect size (ρ=0.128; p=0.473). Although most children had good nutritional status, malnutrition remained prevalent (41.2%). These findings suggest that malnutrition in CHD is multifactorial and cannot be explained solely by the anatomical diameter of the defect.