This article explores the historical development of polygraphy in the Soviet Union, with particular attention to the activities of KGB’s Laboratory No. 30. Drawing on declassified materials, eyewitness accounts, and professional reflections by former KGB personnel, the study reconstructs the evolution of Soviet polygraph practices from the late 1960s to the 1980s. It examines early scientific contributions, the influence of American methodologies, the adaptation of foreign technologies, and the creation of Soviet testing procedures such as the Mixed-Type Test. The article also highlights how Soviet ideological constraints shaped both the official discourse and cinematic portrayals of polygraphy. Special attention is given to the field practices of Laboratory No. 30, including unconventional assignments related to paranormal phenomena. The study concludes that, despite efforts to replicate or adapt Western polygraph techniques, Soviet developments did not result in uniquely innovative methods or technologies. These findings provide a contextual foundation for understanding contemporary polygraph practices in the post-Soviet space, particularly in Ukraine and russia.