There is always a question of when to operate for congenital heart disease that requires surgical treatment, and this is the question of the “best” time to operate. The timing of surgery for children with stable disease is easy to determine, either by referring to textbooks or by following the practices of individual heart centers. However, these textbook descriptions and the customary practice of the cardiac centers often do not cover special patient groups, such as children of a younger age or weight, combined with incurable pneumonia and heart failure, when the timing of surgery should be considered with the principle of maximizing the chances of life safety of the child. For example, in the most common ventricular septal defect, the question of when to operate is generally not a problem for children who can go home and have normal feeding, normal weight, and normal breathing, and it is definitely better for older children. But if the child is not able to feed normally, has difficulty breathing, and does not gain weight, to do or not to do? What’s more, such children are often prone to pneumonia and heart failure, so if conservative medical treatment is not effective, to do it or not to do it? If more consideration is given to the principle of maximizing the child’s chances of life safety, some children, despite their age and weight, and despite the fact that pneumonia is not completely cured, may be better off having surgery early if it is not life-threatening. Therefore, regarding the timing of surgery, it is not a generalization, especially for children with special conditions, “the best time to operate” must be the best time relative to the child, not in the ordinary sense.