The Working Group (Slovak: Pracovná Skupina) was an underground Jewish organization in the Axis-aligned Slovak State during World War II. Led by Gisi Fleischmann and Rabbi Michael Dov Weissmandl, the Working Group rescued Jews from the Holocaust by gathering and disseminating information on the Holocaust in Poland, bribing and negotiating with German and Slovak officials, and smuggling valuables to Jews deported to Poland.

In 1940, SS official Dieter Wisliceny forced the Slovak Jewish community to set up the Jewish Center (ÚŽ) to implement anti-Jewish decrees. Members of the ÚŽ unhappy with collaborationist colleagues began to meet in the summer of 1941. In 1942, the group worked to prevent the deportation of Slovak Jews by bribing Wisliceny and Slovak officials, lobbying the Catholic Church to intervene, and encouraging Jews to flee to Hungary. Its efforts were mostly unsuccessful, and two-thirds of Slovakia's Jews were deported to the Auschwitz concentration camp and camps and ghettos in the Lublin Reservation. Initially unaware of the Nazi plan to murder all Jews, the Working Group sent relief to Slovak Jews imprisoned in Lublin ghettos and helped more than two thousand Polish Jews flee to relative safety in Hungary during Operation Reinhard. The group transmitted reports of systematic murder received from the couriers and Jewish escapees to Jewish organizations in Switzerland and the Aid and Rescue Committee in Budapest.

After transports from Slovakia were halted in October 1942, the Working Group tried to bribe Heinrich Himmler through Wisliency into halting the deportation of European Jews to Poland (the Europa Plan). Wisliceny demanded a $3 million bribe, which far exceeded the Working Group's ability to pay, and broke off negotiations in September 1943. In April and May 1944, the Working Group collected and disseminated the Vrba–Wetzler report by two Auschwitz escapees documenting the murder of hundreds of thousands of Jews. By stimulating diplomatic pressure against the Hungarian government, the report was a major factor in regent Miklós Horthy's decision to halt the deportation of Hungarian Jews to Auschwitz in July. After the Slovak National Uprising in fall 1944, the Germans invaded Slovakia and the Working Group attempted to bribe the Germans into sparing the Slovak Jews. Its failure to clearly warn Jews to go into hiding is considered its greatest mistake.

Most historians agree that the actions of the Working Group had some effect in halting the deportations from Slovakia between 1942 and 1944, although the extent of their role and which of their actions should be credited is debated. The group's leaders believed that the failure of the Europa Plan was due to the indifference of mainstream Jewish organizations. Although this argument has influenced public opinion and Orthodox Jewish historiography, most historians maintain that the Nazis would not have allowed the rescue of a significant number of Jews. It has also been argued that the Working Group's negotiations were collaborationist and that it failed to warn Jews about the dangers awaiting them, but most historians reject this view. Israeli historian Yehuda Bauer considers the Working Group's members flawed heroes who deserve public recognition for their efforts to save Jews.

On 14 March 1939, the Slovak State proclaimed its independence from Czechoslovakia under German protection; Jozef Tiso (a Catholic priest) was appointed president. According to the Encyclopedia of Camps and Ghettos, the persecution of Jews was "central to the domestic policy of the Slovak state". Slovak Jews were blamed for the 1938 First Vienna Award—Hungary's annexation of 40 percent of Slovakia's arable land and 270,000 people who had declared Czechoslovak ethnicity. In the state-sponsored media, propagandists claimed that Jews were disloyal and a "radical solution of the Jewish issue" was necessary for the progress of the Slovak nation. In a process overseen by the Central Economic Office (led by Slovak official Augustín Morávek [cs; de; sk]), 12,300 Jewish-owned businesses were confiscated or liquidated; this deprived most Slovak Jews of their livelihood. Although Jews were initially defined based on religion, the September 1941 "Jewish Code" (based on the Nuremberg Laws) defined them by ancestry. Among the Code's 270 anti-Jewish regulations were the requirement to wear yellow armbands, a ban on intermarriage, and the conscription of able-bodied Jews for forced labor. According to the 1940 census, about 89,000 Jews (slightly more than three percent of the population) lived in the Slovak State.

Dieter Wisliceny, representing Reich Security Main Office Jewish-section director Adolf Eichmann, arrived in Bratislava as the Judenberater for Slovakia in September 1940. His aim was to impoverish the Jewish community so it became a burden on gentile Slovaks, who would then agree to deport them. Wisliceny ordered the dissolution of all Jewish community organizations and forced the Jews to form a Judenrat called the Jewish Center (Slovak: Ústredňa Židov, or ÚŽ). The first such organization outside the Reich and German-occupied Poland, ÚŽ was the only secular Jewish organization permitted; all Jews were required to be members. Leaders of the Jewish community were divided on how to react to this development. Some refused to associate with the ÚŽ in the belief that it would be used to implement anti-Jewish measures, but more saw participating in the ÚŽ as a way to help their fellow Jews by delaying the implementation of such measures. As a result, the ÚŽ was initially dominated by Jews who refused to collaborate and focused on charitable projects (such as soup kitchens) to help those impoverished by the anti-Jewish measures.

The first leader of the ÚŽ was Heinrich Schwartz, longtime secretary of the Orthodox Jewish community, who had been chosen for his fluency in Slovak. Schwartz thwarted anti-Jewish orders to the best of his ability by delaying their implementation. He sabotaged a census of Jews in eastern Slovakia which aimed to move them to the west of the country, and Wisliceny had him arrested in April 1941. Schwartz' replacement was Arpad Sebestyen, who fully cooperated with Wisliceny. However, Sebestyen was aware of the activities of the Working Group and made no effort to stop them or report them to the authorities. Wisliceny formed the Department for Special Affairs within the ÚŽ to ensure the prompt implementation of Nazi decrees, appointing Karol Hochberg (an ambitious, unprincipled Viennese Jew) as its director. Hochberg carried out the removal of Jews from Bratislava, tarnishing the ÚŽ's reputation in the Jewish community. Due to Sebestyen's ineffectiveness, Hochberg's department came to dominate ÚŽ operations.

Dissatisfied with this state of affairs and fearful of voicing their concerns aloud due to Hochberg's influence, during the summer of 1941 many ÚŽ members began meeting in the office of ÚŽ director of emigration Gisi Fleischmann. Fleischmann's office was across the street from the main Jewish Center, which helped keep the group's activity secret. It was eventually formalized into an underground organization which became known as the Working Group. The group included Jews from across the ideological spectrum, working in concert to oppose the Holocaust.