Recently, the U.S. Food and Drug Administration issued an official warning to all practicing physicians regarding potentially detrimental behavioral and cognitive sequelae of an early exposure to general anesthesia during in utero and in early postnatal life. The U.S. Food and Drug Administration concern is focused on children younger than three years of age who are exposed to clinically used general anesthetics and sedatives for three hours or longer. Although human evidence is limited and controversial, a large body of scientific evidence gathered from several mammalian species demonstrates that there is a potential foundation for concern. Considering this new development in public awareness, this review focuses on nonhuman primates because their brain development is the closest to humans in terms of not only timing and duration, but in terms of complexity as well. The review compares those primate findings to previously published work done with rodents.