Pseudoaneurysm (PSA) of the right ventricular outflow tract (RVOT) is an exceedingly rare adverse event after the surgical reconstruction of the RVOT for the treatment of congenital heart disease. We report an unusual giant PSA of RVOT in a 20-month-old child, who underwent correction of the tetralogy of Fallot. Her main symptoms were in the respiratory system, and chest X-ray also revealed the giant space-occupying lesion in the chest, which could've been misdiagnosed as a respiratory disease. After evaluation by the combination of echocardiography and cardiac computer tomography angiogram, the details of PSA were diagnosed, and surgical but not percutaneous intervention was selected. The exclusion of PSA successfully was performed by the femoral cannulation, exploratory through right ventriculotomy, closure of the defect using the Gore-Tex patch, and application of a retained drainage-tube inside the PSA.