After the end of the war and the referendum against the Savoy Monarchy, in 1946, she was elected member of the Constituent Assembly, within the Italian Communist Party. She was also one of the 75 members of the Committee entrusted with the drafting of the Italian Republican Constitution. In the same year, she started her relationship with the communist leader, Palmiro Togliatti, 27 years older than her, which lasted until his death in 1964. Their relationship, which was kept secret in the early years, became of public domain in 1948, after an attempt on Togliatti's life, a few days after the general election. Their love was quite opposed by Italy's public opinion, including many communists, because Togliatti was already married to Rita Montagnana at the time. However, Togliatti forced his wife Rita and their son Aldo, who was mentally ill, to live in Moscow, thus he could continue his relationship with Iotti. Together they asked and obtained the affiliation of an orphan girl, Marisa Malagoli, the younger sister of one of the six workers killed by Carabinieri on 9 January 1950, in Modena, during a workers' demonstration. In April 1948 Iotti was re-elected with the PCI to the Chamber of Deputies, of which she was member without interruption until 1999. In 1956, she became a member of the Central Committee of the Party and in 1962 of the National Direction. Re-elected to the Chamber in 1963, she was appointed in the Constitutional Affairs Commission, focusing her activity on the relevance of the female role in the world of work and family relationships. In the following years, her main commitment turned out to be the reform on civil rights, as the right to divorce. She was paricularly involved in the campaign for the 1974 divorce referendum. After 1979 election, thanks to the support of PCI's historic rival, the Christian Democracy, Iotti became President of the Chamber of Deputies, with 443 votes out of 615. She succeeded another communist, Pietro Ingrao. Iotti focused her first speech in front of the house on women's role in the society as well as the fight on terrorism. She was popular and respected as a president, and was confirmed in the office for two more legislatures. In 1987, she was entrusted by President Francesco Cossiga with a mandate of potentially forming a government. She became the first communist and the first woman to have ever received an exploratory mandate to become Prime Minister of Italy; however, Iotti was not able to form a coalition. In 1992, the name of Nilde Iotti was mentioned for the election of the President of the Italian Republic.
Personal life
She was an atheist.
Death
She died in Rome on 4 December 1999 and she is buried in the Cimitero del Verano.