This paper seeks to make a contribution to our understanding of the specifics of racial policy practice in the Third Reich as well as the racial certification process at Otmar von Verschuer's Institute for Human Heredity and Racial Hygiene. I will focus on a recent and heretofore uninvestigated archival find intricately linked to National Socialist racial policy: 247 racial certificates completed in von Verschuer's research center between 1936 and 1945. An analysis of the racial certificates constructed at von Verschuer's Frankfurt Institute can hence disclose valuable information on the relationship between National Socialist racial policy and practice. Moreover, it raises the contested issue of whether or not such ancestral examinations based on the concept of “Jewish racial traits” were undertaken according to “scientific criteria” of the day, while simultaneously demonstrating the sometimes subtle, sometimes not-so-subtle, mixture of ideological prejudice and scientific practice as they combined in these examination procedures. Finally, considering the nefarious collaboration between von Verschuer and his protégé Josef Mengele during the war years and the historiographical preoccupation with their medical offences, it is also worth asking whether von Verschuer and his former student's duties as “racial experts” can help explain why they decided to undertake their notorious investigation of “specific proteins” at the world's most infamous death and slave labor camp.