By using several case studies, the article shows how the attitudes of paediatricians and state actors towards the involvement of the former Professor of Paediatrics at Leipzig University, Werner Catel, in National Socialist “child euthanasia” in the Soviet Zone of Occupation / German Democratic Republic changed over the decades. These interactions were shaped by very different motives, in particular by political opportunism, by moral convictions, and by the loyalty towards colleagues. On the one hand, the attitude of the state actors was strongly influenced by the GDR’s self-understanding as an anti-fascist state as opposed to the Federal Republic, and, on the other hand, by pragmatic considerations and overarching political decisions. These case studies are situated in the context of the current historiography of medicine, and, more broadly, the contemporary entangled history of both German post-war states and the emergence of commemorative cultures in East and West.