ENThe study of Lithuania's nuclear past consists of three parts. Part one discusses the key directions of the research in nuclear physics, conducted by Lithuanian scientists, and the training of specialists in the field of nuclear engineering. Part two deals with the circumstances of construction of the Ignalina Nuclear Power Plant, Lithuania's most important nuclear facility. The deployment of the Soviet Union's nuclear weaponry in Lithuania is discussed in part three. The study was performed by the representatives of the Institute of Physics, the Lithuanian Energy Institute, and the Institute of International Relations and Political Sciences of Vilnius University. [p. 5].