Introduction:Explicit outcomes routinely measured acrossthe life span following hypospadias surgery, defined by acore outcome set (COS), will harmonize and overcome re-porting heterogeneity.Methods:Age-specific outcomesidentified in a literature review were presented in a three-round Delphi survey. Participants (professionals, parents,and patients) were encouraged to suggest outcomes in thefirst Delphi round. In subsequent rounds, participants wereasked to choose and rank up tofive preferred outcomes foreach age. To be deemed core, an outcome needed over 70%of votes in a round.Results:Professionals were mainlypaediatric urologists (rounds 1, 2, 3:n= 57 [77%], 39 [78%],35 [81%]). The response rates from parents/patients (rounds1, 2, 3:n= 17, 5, 3) were low. In young boys (<6 years, 10-11years), four core outcomes were identical (voiding,fistula, re-operation, and urethral stricture). Core outcomes in boysaged 11-16 years (cosmesis, curvature, voiding, stricture,and psychosocial status) and boys>16 years (cosmesis,curvature, erection, voiding, and psychosexual develop-ment) varied more.Conclusion:Outcomes to include in aCOS were consistent in younger boys. A larger variety wasobserved in older boys and reflects less clarity on relevantoutcomes.(c) 2025 S. Karger AG, Basel