This paper considers some demographic aspects of the world's Moslem population.  Main sources of information are evaluated, and a definition is laid down for a Moslem country.  Proportions of Moslem population are given for some 20 Asiatic and 30 African countries.  Geographical distribution of Moslem countries as well as of the total world population are studied in some detail with due attention being devoted to Moslem minorities in non-Moslem countries such as China and the USSR.  Population density, annual growth rate, life expectancy, age and language distributions are among the demographic features discussed comparatively at country and continent levels.  Special attention is given to urbanization in the Moslem world.  Finally future trends are discussed by using the usual statistical methods.  It is thus established that by the year 2000 the proportion of world's Moslem population will rise to 22.4% as compared with 18.3% in 1975 and that the pressure on natural resources of the Moslem countries will be more than twice that in 1975 which is an alarming fact.  It is hoped that the study will assist Moslem leaders in adopting sound population policies in their respectivie countries.