After a schism at the end of 1970, the main group of the leaders moved from Rome to Milan.

On 15 April 1972 the UCI(m-l) was transformed into Italian (Marxist–Leninist) Communist Party (Partito Comunista (marxista-leninista) Italiano).

With the appearance of the Leninist poet Francesco Leonetti in the party, the theoretical organ of PC(m-l)I became known as Che fare.

The PC(m-l)I had a front organization amongst Italians in West Germany, called Union of Italian Migrant Workers (Federazione Italiani Lavoratori Emigrati).

The PC(m-l)I was dissolved in 1978, and its remaining adherents largely became involved in Autonomia Operaia.