The article summarizes trends in fertility over the period 1960-1995 for major developing regions and reviews of developing country demographic trends since 1960 which demonstrates that fertility decline has occurred in a wide range of economic, social, and cultural circumstances and that it will probably become universal in the near future. It is argued that the huge gains in life expectancy that occurred in the twentieth century constitute the most plausible underlying cause of the near ubiquitous falls in fertility. However, explanations of the precise timing and speed of national fertility transitions need to take into account many other factors.