Due to differing views and lack of documentation, estimates for the number of Serbian victims in Croatia range widely, from 25,000 to more than one million. The estimated number of Serbs killed in Jasenovac ranges from 25,000 to 700,000. The most reliable figures place the number of Serbs killed by the Ustaša between 330,000 and 390,000, with 45,000 to 52,000 Serbs murdered in Jasenovac.
Germans and Ustaša killed approximately 32,000 Jews from Croatia between 1941 and 1945. The precise number of Jews murdered in the Jasenovac complex is not known, but estimates range from 8,000 to 20,000 victims. These numbers do not include Jews whom the Ustaša authorities turned over to the Germans for deportation to Auschwitz and other camps.
Statistics for Romani victims are difficult to assess, as there are no firm estimates of their number in prewar Croatia and Bosnia-Herzegovina. The best estimates calculate the number of Romani victims at about 26,000, of whom between 8,000 and 15,000 perished in Jasenovac.
There are only loose estimates for the number of Croats murdered by the Ustaša. This group included political and religious opponents of the regime, both Catholic and Muslim. Between 5,000 and 12,000 Croats are believed to have died in Jasenovac.
There are no reliable statistics on the number of Muslim victims. The Muslims from Bosnia-Herzegovina were ethnic Slavs and spoke a variety of Serbian and Croatian dialects. Croatian nationalists as well as the radical Ustaša leaders perceived all Muslims in Bosnia-Herzegovina as Croats; the regime aimed to convert them to Catholicism. They were persecuted for religious and political rather than racial reasons.
http://www.ushmm.org/museum/exhibit/online/jasenovac/