Hallervorden–Spatz disease (HSD) has been recently renamed to pantothenate kinase-associated neurodegeneration (PKAN) and neurodegeneration with brain iron accumulation (NBIA), mainly due to the unethical behavior of Julius Hallervorden in the National Socialist (NS) euthanasia program of the Nazi Third Reich. The role of the second name giver in the NS euthanasia program is less clear. Hugo Spatz was the director of the Kaiser Wilhelm Institute for Brain Research in Berlin-Buch during World War II (WWII), renamed to Max Planck Institute after 1945. After the war, he headed the Max Planck Institute for Brain Research in Frankfurt am Main. The present study investigates the potential involvement of Hugo Spatz in the NS euthanasia program. In the present study, we compared a list of euthanasia victims from the German Federal Archive Berlin (30.146 cases published after the reunification of Germany, BArch R179) with the files of the collection of specimens from 1940 until 1945 of Hugo Spatz as listed in the Archive of the Max Planck Society Berlin-Dahlem (n = 305). Furthermore, the old term HSD and the new terms PKAN and NBIA were systematically searched in PubMed from 1946, through January 2019 to evaluate the renaming process from HSD to PKAN/NBIA. Following Hugo Spatz’s death in 1969 growing evidence indicated that he may have taken part in the NS euthanasia program. This study identifies 4 euthanized victims in the patient files of Hugo Spatz from 1940 to 1945, suggesting involvement of Hugo Spatz in the NS euthanasia program. This further strengthens the argument that the former HSD should be exclusively referred to as PKAN or NBIA.