Accelerated idioventricular rhythm was observed in three newborn infants with congenital heart disease. This ventricular arrhythmia in all of our patients did not alter the clinical features of the congenital heart disease, and it disappeared at the ages of 84 days, 40 days, and 45 days, respectively. This arrhythmia is generally considered to be benign, which also appears to be the case with the newborn infant with congenital heart disease.