In the First Italian Republic, after the Second World War, many armed, paramilitary, far-right organizations (Italian: organizzazioni armate paramilitari di estrema destra) were active, as well as far-left ones, especially in the Years of Lead.

The attempt to endorse the Italian Social Movement (MSI), a neo-fascist heir of the National Fascist Party, by the Tambroni Cabinet in 1960 led to rioting and was short-lived.^[1] Widespread labor unrest and the collaboration of countercultural student activist groups with working class factory workers and pro-labor radical leftist organizations, such as Potere Operaio and Lotta Continua, culminated in the Hot Autumn of 1969, a massive series of strike actions in factories and industrial centres in Northern Italy.^[1] Student strikes and labour strikes, often led by workers, leftists, left-sympathizing laborers, or Marxist activists, became increasingly common, often deteriorating into clashes between the police and demonstrators composed largely of workers, students, activists, and often left-wing militants.^[1]

In the same period, various organizations with a far-right ideology emerged in Italy and undertook violent action. Young neo-fascists perceived the legal, neo-fascist political party MSI as betraying them through its ostensible inaction in the face of attacks by the police and political opponents, as in the case of the Acca Larentia killings.^[2] Influenced by theories of urban guerrilla warfare and spontaneism,^[3][4] a number of neo-fascists moved from street-fighting to terrorism.^[5]

• Left-wing militant groups in Italy
• Italian fascism
• Palingenetic ultranationalism
• Post-fascism in Italy
• Radical right (Europe)
• Right-wing populism
• Right-wing terrorism
• Ultranationalism