We report the case of a 21-year-old woman with a severely stenotic pulmonary homograft who underwent percutaneous pulmonary valve implantation, with no significant change in transvalvular gradient within the 24 hours after the procedure. Major improvement in hemodynamic valve performance of more than 60% decrease in transvalvular gradient and more than 30% increase in pulmonary valve area was observed 3 months after the procedure, showing that hemodynamic improvement can occur late after pulmonary valve implantation. An echocardiogram after 3 months should be done before concluding the procedure failed and that reintervention is necessary.