AbstractNoonan syndrome (NS) is a common genetic syndrome with a high variety in phenotype. Even though genetic testing is possible, NS is still a clinical diagnosis. Feeding problems are often present in infancy. We investigated the feeding status of 108 patients with clinically and genetically confirmed NS. Only patients with a documented feeding status before the age of 6 were included. A distinction was made between patients with early onset feeding problems (< 1 year) and children with late onset feeding problems (> 1 year). Seventy-one of 108 patients had feeding problems, of which 40 patients required tube feeding. Children with a genetic mutation other than PTPN11 and SOS1 had significantly more feeding problems in the first year. Fifty-two of all 108 patients experienced early onset feeding problems, of which 33 required tube feeding. A strong decrease in prevalence of feeding problems was found after the first year of life. Fifteen children developed feeding problems later in life, of which 7 required tube feeding.Conclusion: Feeding problems occur frequently in children with NS, especially in children with NS based on genetic mutations other than PTPN11 and SOS1. Feeding problems develop most often in infancy and decrease with age. What is Known:• Young children with Noonan syndrome may have transient feeding problems.• Most of them will need tube feeding. What is New:• This is the first study of feeding problems in patients with clinically and genetically proven Noonan syndrome.• Feeding problems most often develop in infancy and resolve between the age of 1 and 2.