In December 1942, Himmler signed an order for the deportation of all Roma in Germany. Although Himmler permitted certain exceptions from deportation, they were often ignored on the local level. Even German army (Wehrmacht) soldiers home on leave were seized and deported for being Roma.

Roma in Germany were deported to Auschwitz, where a special camp was designated for them in Auschwitz-Birkenau--the "Gypsy family camp." Entire families were incarcerated together. Twins and dwarves, however, were separated out and subjected to pseudoscientific medical experiments under SS Captain Dr. Josef Mengele. Nazi physicians also used Romani prisoners in medical experiments at the Ravensbrueck, Natzweiler-Struthof, and Sachsenhausen camps.

The "Gypsy family camp" at Auschwitz was riddled with epidemics--typhus, smallpox, and dysentery--which severely reduced the camp population. In May 1944, the Germans decided to liquidate the camp. As the SS surrounded the camp, they were met by Roma armed with iron pipes and the like. The Germans retreated and postponed the liquidation. Later that same month, the SS transferred about 1,500 Roma who were still capable of work out of the family camp. Almost 1,500 more were transferred in August. The remaining Roma, about 3,000, were killed. At least 19,000 of the 23,000 Roma sent to Auschwitz died there.

In German-occupied areas of Europe, the fate of Roma varied from country to country, depending on local circumstances. The Nazis generally interned Roma and later transported them to Germany or Poland for use as forced laborers or to be killed. Many Roma from Poland, the Netherlands, Hungary, Italy, Yugoslavia, and Albania were shot or were deported to extermination camps and killed. In the Baltic states and the German-occupied areas of the Soviet Union, Einsatzgruppen (mobile killing units) killed Roma at the same time that they killed Jews and Communist leaders. Thousands of Romani men, women, and children were killed in these actions. Many Roma were shot along with Jews at Babi Yar, near Kiev, for example.

In France, authorities implemented restrictive measures against Roma even before the German occupation of the country. Deportations of Roma began from occupied France shortly toward the end of December 1941. In the unoccupied zone, Vichy officials under the supervision of Xavier Vallat and the Ministry for Jewish Affairs interned about 3,500 Roma. Most of them were later sent to camps in Germany such as Buchenwald, Dachau, and Ravensbrueck.

The Romanians did not implement a systematic policy of extermination of Roma. However, in 1941 and 1942 between 20,000 and 26,000 Roma from the Bucharest area were deported to Transnistria, in the Romanian-occupied Ukraine, where thousands died from disease, starvation, and brutal treatment. In Serbia, in the fall of 1941, German army (Wehrmacht) firing squads killed almost the entire adult male Romani population, alongside most adult male Jews, in retaliation for the killing of German soldiers by Serbian resistance fighters. In Croatia, the Ustasa (Croatian fascists allied with Germany) killed as many as 26,000-28,000 Roma. Many Roma were interned and killed at the Jasenovac concentration camp.

It is not known precisely how many Roma were killed in the Holocaust. While exact figures or percentages cannot be ascertained, historians estimate that the Germans and their allies killed between 25 and 50 percent of all European Roma. Of the approximately one million Roma living in Europe before the war, up to 220,000 were killed.

After the war, discrimination against Roma continued as the Federal Republic of Germany decided that all measures taken against Roma before 1943 were legitimate policies of state and were not subject to restitution. Incarceration, sterilization, and even deportation were regarded as legitimate policies. Further, the Bavarian criminal police took over Robert Ritter's research files, including his registry of Roma in Germany. Ritter, the Nazi racial expert on Roma, retained his credentials and returned to his former work in child psychology. Efforts to bring Dr. Ritter to trial for complicity in the killing of Roma ended with his suicide in 1950.

German chancellor Helmut Kohl formally recognized the fact of the Nazi genocide against Roma in 1982. By then, most of the Roma eligible for restitution under German law had already died.