Preliminary census results show Bosnia's population has dropped by nearly 13 percent since the country's 1992-95 war.
Bosnia's Statistics Agency director Zdenko Milinovic says nearly 3.8 million people were registered in the country during the census last month. In the last census, taken in 1991, Bosnia had a population of 4.4 million made up of 43.7 percent Muslims, 31.4 percent Serbs and 17.3 percent Croats.
Results on the country's current ethnic composition are expected early next year.
More than 100,000 people were killed in the Bosnian war, while another two million became refugees.
The country remains divided along ethnic lines, split into two highly autonomous, ethnically-based regions: the Federation, dominated by Muslims and Croats, and the Serb Republic, dominated by Serbs.