Dermatologists are often faced with the decision of when to operate on a child at risk for developing malignant melanoma in a large congenital nevocytic nevus. As a series of operations is usually required, an understanding of the lethal and nonlethal effects of the general anesthesia is necessary. This paper discusses these potential iatrogenic effects on the child's physical and psychological development. Suggestions are given for optimal times to operate, considering both psychological and physical factors, (i.e., 6-9 months or 8-12 years of age) and ways to minimize unwanted side effects.