In Caracas he was part of the clandestine organization of Acción Democrática which, in coordination with the leadership in exile, established an organised resistance to the military dictatorship. Lusinchi acquired responsibilities in the national secretariats of organization and propaganda, and was a member of the party's Political Bureau. In 1950 he was one of the organizers of the nationwide strike of oil workers. After the 1952 election fraud, which dissolved the Civilian-Military Junta and began the dictatorship of Marcos Pérez Jiménez, Lusinchi was again captured and imprisoned at the National Security facility.