For more than half a century, nuclear energy has been among the main issues of public concern, and thus of political, social as well as environmental debate. Nuclear energy has generated a long-standing controversy that began with the atomic bombs on Hiroshima and Nagasaki which comprise one of the most crucial turning points of contemporary history, from WWII up to the present. This paper aims to deal with a shorter period within this long and still controversial history. It focuses on the 1970s, when in Italy—as well as in the United States and Western Europe—the 1973 oil crisis made clear the need to diversify energy supply sources. As a result, national and international interest in nuclear power increased. The transition to a fully-fledged nuclear industry was to be achieved by the end of the century, with the launch of the first fast breeder reactors (FBRs). In Italy, the National Committee for Nuclear Energy (Comitato Nazionale per l’Energia Nucleare - CNEN), in agreement with the National Electricity Board (Ente Nazionale per l’Energia Elettrica - ENEL) and the newly established regional political bodies (Regional Councils), were entrusted with the task of drawing up the national map of sites suitable for nuclear facilities, and especially for nuclear power plants. The paper aims to provide an overview of the main geological issues that fueled the Italian ‘nuclear siting controversy’ during the 1970s. It focuses also on some still unpublished topics, such as those about the ENEL–CNEN Joint Study Commission for the Seismic Problems Associated with the Installation of Nuclear Plants and the drafting of a first national map of areas suitable for radioactive waste repositories. The matters under discussion here are significant because of the link with some key issues still open in contemporary debates on nuclear energy, such as planning and siting of nuclear facilities. It is also worth noting that some current global emergencies (e.g., the war in Ukraine and climate change) have brought the European, and more generally international, debate back to the urgency of energy diversification, including nuclear power in the energy generation mix. Historical analysis, although focused on particular case studies from the past, can help to better understand such a complex issue.