The Holocaust of the Jewish population in Europe during the Second World War is widely known. Poland's population in 1939 was 34.8 million, of which 3.4 million were Jews. No other European country could even come close to the number of Jewish people living within its borders. The Germans, ever efficient and practical and having decided on the extermination of the Jews, earmarked Poland as a place to carry out their plan, as this would minimize transportation effort. In 1940 the first ghettos were established, among those the Warsaw Ghetto, where Jewish people were initially allowed to exist. Concentration camps were also set up by the Germans throughout Poland. Auschwitz, the largest of the camps, was initially used for Polish prisoners. On June 14, 1940, the first 728 Polish prisoners were brought to Auschwitz, and for the next twenty-one months the camp was inhabited almost exclusively by Poles. The first transport of fifteen hundred Jews arrived to Auschwitz on May 12, 1942. It is estimated that the victims of the Auschwitz-Birkenau concentration camp alone number approximately 1,500,000, of whom most were Jews and 150,000 were Christian Poles.

On April 19, 1943, when the Germans began the final liquidation of the Warsaw Ghetto, about six hundred Jewish fighters started an uprising which, with materiel help from the Polish underground Home Army, lasted until May 16, 1943. At this time, all of the Jews were murdered by the Germans, except for a few who escaped from the ghetto through sewers with the help of the underground Polish Home Army. German losses in the uprising were three hundred killed and one thousand wounded.

Poland was the only country in German-occupied Europe where hiding Jews was punishable by death. The penalty applied equally, and without regard to age or gender, to the hidden Jews and to all Christian members of the host family. Despite this, of all the European nations, Poland saved the greatest number of Jews. Indeed, on December 4, 1942, in cooperation with the Polish Government in Exile in London, Polish underground organizations in occupied Poland established the underground organization "Żegota" in Warsaw, exclusively dedicated to saving and helping the Jews. Żegota provided living quarters, false documents, food, medical care and financial help to the Jews in what was a difficult and dangerous operation. Many Hassidic Jews, especially in the provinces of eastern Poland, wore distinctive black attire which, in addition to their features, immediately betrayed their Semitic origin. Therefore, it was imperative that they stay indoors at all times, supplied with necessary provisions from Żegota members.

Many Jewish children were saved in monasteries and convents by religious order nuns. In these circumstances, the children were taught Christian prayers and were often baptized for security reasons, in case of German inspections, and in some cases because of the missionary zeal of the nuns. Many Jews and rabbis resented this and to this day often harbor anger for conversions of the children into Christianity. But overall, the greatest number of Jews saved in Poland during that time were saved by individual Polish families.