In 1947, while a student at the Carol I High School in Craiova, he joined the anti-communist resistance group led by general Ioan Carlaonț.

[5] He was interrogated by the Securitate and the NKVD,[1] and sentenced to 15 years of imprisonment with hard labor for having laid the foundations of "a subversive organization with a terrorist character" and for "purchasing weapons, ammunition and explosives, with the aim of removing the regime and to fight against the Soviet Union, through actions of sabotage and insurrection.

"[6] Ciuceanu was detained at penitentiaries in Craiova, Jilava, Târgșor, Pitești, Gherla, Aiud, Văcărești, and Dej, as well as at the Poarta Albă forced-labor camp on the Danube–Black Sea Canal.

[3][4][7] While at Pitești Prison, starting in 1949, he was tortured (by, among others, Eugen Țurcanu[5][6]), as part of the notorious re-education experiment supervised by the Securitate general Alexandru Nicolschi.

In 1993 Ciuceanu founded the National Institute for the Study of Totalitarianism [ro] (under the aegis of the Romanian Academy), which he led as director for 3 decades.