Does anesthesia affect the mental development of infants or not? If so, which is better: general anesthesia or local anesthesia? This multi-country, multi-center study from 28 hospitals in 7 countries around the world answers this question well. In this study, 363 infants aged less than 60 weeks without neurological impairment were randomized at the time of surgery into a general anesthesia group and an awake regional anesthesia group (local anesthesia as understood by the population) between 2007 and 2013, with general anesthesia using sevoflurane and a mean anesthesia time of 54 minutes, and the children were evaluated at two and five years of age, respectively, using international intelligence testing criteria. Only the results of the test at the age of 2 years are reported in this thesis. The results suggest that for infants, there is no difference between sevoflurane general anesthesia over 1 hour and regional anesthesia under awake (which can be interpreted as local anesthesia) to monitor neurodevelopment, at least when the children are two years old. The countries involved in this work were the United States, the United Kingdom, Australia, Italy, Canada, the Netherlands, and New Zealand. The breadth of countries involved and the length of time involved is remarkable. But it does answer the concerns of a wide range of parents. The researchers found no evidence that sevoflurane anesthesia, which takes less than an hour in infancy, increases the risk of adverse neurodevelopmental outcomes at age 2 years compared with local anesthesia.