The main purpose in preparing this bulletin is to assemble so far as practicable and publish in brief form such official statistics as are available on illiteracy in the various countries of the world, to tell where those data may be found, and if possible, to give a general estimate of world-wide illiteracy. Incidental to this purpose, it becomes necessary to show the high percentage of the world's population for which statistics of illiteracy are not gathered; to indicate the unreliability of many of the popularly quoted statistics; and to voice the need for common criteria in determining what illiteracy is and the age groups to which they should apply, in order that the data may be more comparable and a truer picture of the status of illiteracy may be possible. The schedules for the censuses of the countries of the world of 1930 and thereabouts will soon be arranged. It is hoped that the various kinds of data here presented will, to some extent, help the makers of those schedules to arrange schemes for collecting and reporting that are more nearly common to all countries, so that by 1935 the figures may be presented more clearly, definitely, and comprehensively. Contents include: (1) Introduction; (2) Statistics of illiteracy; (3) Areas of least illiteracy; (4) Political divisions with illiteracy rates between 10 and 50 percent; (5) Political divisions with population over half illiterate; (6) Summary of data presented and of areas for which adequate data are not given; (7) Is illiteracy decreasing?; (8) Illiteracy and age groups. (Contains 6 tables and 6 maps; individual chapters contain footnotes.) [Best copy available has been provided.]