This dissertation follows the transformations in Russian biomedical epistemology occasioned by the collapse of the Soviet Union. The analysis focuses on the epistemic foundations of Russian biomedical science-what counted as valid clinical evidence, what the appropriate methods for producing such evidence were, and who got to make these decisions-and how these criteria, methods and power relations have changed in response to the collapse of the Soviet political economy and the introduction of a capitalist system. Drawing upon extensive archival research as well as ethnographic data, the analysis proceeds on three levels-that of institutions and organizations, practices, and ideas and rhetoric. On the level of institutions and organizations, the project focuses on the Soviet system of health protection, particularly those institutions within it that were involved in biomedical research and science policy, and examines their operation in the context of the Soviet-American exchange in oncology during the 1970s. On the level of practices, it examines Soviet drug development efforts in oncology, paying particular attention to clinical trial practices. And on the level of ideas and rhetoric, it traces two attempts to revise biomedical knowledge production and knowledge application practices. The first takes place in the Soviet period, and centers on the attempt to introduce the methods and concepts of cybernetics into Soviet biomedicine. The second takes place after the fall of the Soviet Union, and centers on the attempts to integrate the epistemic commitments of evidence-based medicine into Russian medical practice.