As stated in the preface of this publication, “Americans travel abroad more than the nationals of any other country—today more than any other time in history.” For the convenience of those planning to travel, the United States Public Health Service has prepared this excellent booklet which presents in a concise way the immunizations required for traveling abroad. Under the International Sanitary Regulations of the World Health Organization, the health authorities at ports of arrival may, under certain conditions, apply sanitary measures to and require certificates of vaccination from travelers to prevent the spread of the six quarantinable diseases. In this publication, the immunizations requested by 200 countries and territories are listed by continents and by alphabetical order within the continent for easy reference. Information is also given on immunizations other than those enforceable under the international agreements, which are recommended—as an added precaution—either by the countries themselves or by the United States Public Health Service.