Judges in The Hague have acquitted Radovan Karadzic of one count of genocide, but left ten other war crimes and genocide charges standing against the former Bosnian Serb leader.
Judges ruled that there was not enough evidence to show that killings carried out by Bosnian Serb forces in the municipalities of Bosnia in 1992 were committed with genocidal intent.
But they rejected defence motions to dismiss ten other charges that included the 1995 killings of 8,000 Muslims in Srebrenica, Europe's worst massacre since World War II.
Mr Karadzic was leader of the Bosnian Serb government during the three-year war that raged in Bosnia from 1992 after the break up of Yugoslavia.
He was indicted for war crimes and genocide by the International Criminal Tribunal for the former Yugoslavia in 1995 and brought to The Hague 13 years later.
His trial, under way since 2009, continues later this year with the opening of his defence case.