The World Health Organization says people make a total of 93 million blood donations worldwide every year, but the rate of donation in poor countries is far too low.
The agency says one percent of a country's population has to give blood to collect enough for the basic needs for blood transfusions. WHO says the donation rate is below 1 percent in 77 countries.
It says half of the global blood donations are collected in developed nations, home to only 16 percent of the world's population.
WHO says only 47 percent of blood donations in developing countries are properly screened for infections.
The agency published the figures Friday before World Blood Donor Day on June 14.
It says the data is from 2007 and 2008, the most recent years available.