At some point in America in the 1940s, T. D. Lysenko's neo-Lamarckian hereditary theories transformed from a set of disputed doctrines into a prime exemplar of "pseudoscience." This paper explores the context in which this theory acquired this pejorative status by examining American efforts to refute Lysenkoism both before and after the famous August 1948 endorsement of Lysenko's doctrines by the Stalinist state, with particular attention to the translation efforts of Theodosius Dobzhansky. After enumerating numerous tactics for combating perceived pseudoscience, the Lysenko case is then juxtaposed with another American case of alleged pseudoscience: the notorious 1950 scandal surrounding Immanuel Velikovsky's Worlds in Collision (1950, Worlds in Collision. New York: Macmillan). On several levels, the characterization of Lysenkoism as pseudoscientific served as a template for casting other rejected theories, including Velikovsky's, in the same light.