In the decade before Hitler's seizure of power, Nazi race theorists had the foundations laid for them by such "gypsy specialists" as the criminal psychologist Dillmann and Anton Obermayer. These "professionals" described Roma itinerant labour as a "cover for their asocial behaviour"; all Roma were classified as a "racial" entity with "antisocial" and "criminal" characteristics. Roma were not often cast as potential threats to the "purity of the Aryan race" at first, but they were gradually perceived as being an "sore on the body of the German race". Their alternative, "unbourgeois" lifestyle, for the most part still one of travel, must also have posed a challenge to the totalitarian Nazi state, which concentrated at first mostly upon Jews.

In the mid-Thirties Nazi scientists from various disciplines began to look closer at Roma. Upon analysis of this racist body of work from between the years 1933 and 1938, it becomes clear how the scientific community's "approval" of Roma decreased steadily. The public was constantly warned against "mixing races", against "relationships with the lowly members of a subservient people" and there were oft-repeated demands to have the "mixing of two vastly different races" studied as quickly as possible. Other Nazi scientists pointed to the parallels between Roma and Jews: "Jews and Gypsies are to-day greatly removed from us because their Asiatic ancestors were completely different to our Nordic forebears in terms of race". They also asked why the Nazi state took an interest in Roma relatively late: "they do not pose as great a racial threat as the Jews thanks to their small number, approximately 20,000, along with their intellectual inferiority and their asocial lifestyle, hindering their entry into our race's leader class as Jews have done". According to Krämer however, Roma were politically as dangerous as Jews: "with the subhuman's instinct they recognised the weaknesses of the [Wilhemine] state and turned to support Communism".

The very first decrees and laws issued by the Nazi state impinged on the country's itinerant population. The 1933 "Congenitally Transmitted Diseases law" was directed against the Yenish above all and led to the forced sterilization of members of this ethnic group. The 1933 "Regulations for Security and Improvement" were similarly aimed at the above-mentioned people. The "Dangerous repeat Offenders Law" of April 24th 1933 prescribed transportation to a concentration camp upon repeat of an offence; many Roma were convicted under this law, the Nazi state intent on casting them as criminals (e.g. because of their infringement of Meldegesetzte, the legal obligation to report and register your place of residence). In 1934 it became legal to deport Roma who could not prove their citizenship. In 1935 the German representative at the international meeting of criminal police forces in Copenhagen suggested that "incorrigible Gypsies" should be subjected to forced sterilisation. In right-wing clerical Vienna, an "International Centre against Gypsy Disorder" was opened in 1936, probably under pressure from Germany. The first transports to detainment camps had started in 1933; as early as 1936, 400 were transported to Dachau. 1936 also saw the issuing of a whole string of new discriminatory measures.

Unlike Jews, Roma were not specifically singled out in neither the Nuremberg Laws of 1935, laws which differentiated between "residents" and "citizens", nor in the "Law for the Protection of German Blood and German Honour" which forbade that marriage between Jews and non-Jews. The following year, Stuckart and Globke went to great lengths to show up this laxness (1936: "Jews and Gypsies are generally the only representatives of alien blood"), as did Brandis-Massfeller (1936: "apart from Jews the only members of an alien people in Europe are really Gypsies"). In his 1937 commentary on the "Laws for the Protection of German Blood", Schäffer demanded that not only Jews be targeted but also "Negroes, Gypsies and bastards". Citizenship was denied to Roma and Jews; from 1943 they would also be without their status as residents, something they were allowed to keep until then as "ethnic aliens"