Background
 It is not known at which size a congenital Patent ductus arteriosus (PDA) in children becomes associated with a resultant severe malnutrition in children. Furthermore, the effect of ductal size on anthropometry of children with PDA is yet to be determined.
 Objectives
 This study was aimed to asses if the ductal size had any effect on anthropometry of children with PDA and at which size evidence of severe malnutrition ensues
 Methods
 This was a five-year observational cross-sectional study of children who presented at three tertiary institutions with PDA.
 Results
 There was a negative non-significant correlation between the size of PDA and the weight of patients, (Pearson correlation coefficient = -0.1, p = 0.7). There was also a negative non-significant correlation between the size of PDA and patient’s height/length, (correlation coefficient = -0.1, p = 0.5).
 The association between the size of PDA and the severity of malnutrition revealed greater proportion of 35.3% (6/17) for wasting and stunting in patients who had large PDA sizes of >7mm, when compared with fewer proportions in those with PDA sizes of 3- 6mm (26.1% (6/23) and those with tiny PDA of <3mm (33.3% (10/30); (χ2 = 10.21, p = 0.8).
 There was a positive correlation between ductal size and nutritional status of patients, and severe malnutrition ensued from ductal size of 3.2mm; with ETA square of 0.072.
 The majority of children with PDA presented with severe forms of malnutrition (wasting and stunting).
 Conclusion: Severe malnutrition ensues when ductal size is 3.2mm. The size of PDA has no effect on weight and height of children with PDA.