More than one million people, mainly European Jews, were killed at Auschwitz by German forces during the occupation. Birkenau was the neighboring camp and the site of the main gas chambers and crematoriums.
Polish political prisoners, prisoners of war from the Soviet Union, Gypsies, homosexuals, people with disabilities and prisoners of conscience or religious faith also died at the camp.
"Unesco has made a decision as a result of Poland's request to change the name of Auschwitz Birkenau to reflect the historical truth," Kazimierz Ujazdowsk, Poland's culture minister, said. "This is a victory for truth".
On Wednesday, a German politician heavily criticised the Polish government for using Germany's Nazi past in an attempt to secure improved voting rights at an EU parliament hearingr.
Martin Schulz, Socialist Group leader, won loud applause as he denounced the tactics of Warsaw's ruling Kaczynski twins.
"Anybody who tries to bargain the dead of the Second World War against votes in the [EU] Council has to be rejected out of hand," he said, referring to the EU body where decisions on the 27-member bloc's key policies are taken.
The EU is an idea aimed at eliminating the spectres of the past ... We will not permit the few to bring up those spectres."
Jaroslaw Kaczynski, Poland's prime minister, stunned EU counterparts by suggesting more voting powers were deserved because its population would be much larger were it not for Nazi Germany.
Poland eventually won concessions after a marathon haggling session, notably a delay to the introduction of the planned new voting system which it vehemently opposed, but faced criticism for its hardball negotiating style.
Jean-Claude Juncker, Luxembourg's prime minister, told a German newspaper he was "pained" by the Polish position.
"Those who rule Poland now have not accepted within themselves the reconciliation with Germany," he told Rheinischer Merkur in an interview published on Thursday.