Several experimental studies have demonstrated the adverse effects of anesthetic agents on the developing brain. Most of these agents appear to induce apoptosis of immature neurons and could interfere with the development of dendritic arborization. Extrapolation of experimental data to clinical settings is uncertain because of the pharmacokinetic and pharmacodynamic differences between the diverse species. No prospective clinical studies deal with this question. Several recent epidemiologic studies nonetheless suggest a potential association between anesthesia and long-term damage to cognitive functions. In studying the potential effect of general anesthetics on the immature human brain, it is difficult to separate the effects of anesthesia from the effects of the surgery. Several prospective studies are currently underway to elucidate this important question.