The IMS was founded by Joe Deasy (1922–2013), Sam Nolan (1930-), Paddy Carmody, George Jeffares, Mick O'Reilly (1946-) and other former CPI members.

[6] The CPI strongly criticised the Anglo-Irish Agreement, claiming the AIA "underlined Partition and gave Britain a direct say in the affairs of the Republic".

[7] In the 1980s, its membership declined significantly during the electoral rise of the Workers' Party and this trend continued after the dissolution of the Soviet Union.

The party's aim is to win the support of the majority of the Irish people for ending the capitalist system and for building socialism.

Autobiographical accounts of the party in this period have been written by Mick O'Reilly,[8] Helena Sheehan[9] and Kevin McMahon.

[14] On 2 June 2021, the CPI released a statement distancing itself from its former Belfast branch due to the actions of former party members in the city.

The CPI blamed the war on "the expansion of NATO", stating it had built up "large bases of troops and mass destructive weapons along [Russia's] western and southern borders".

[18] In 2022, a group seceded from the CPI, citing "political and organisational issues", with the name "Irish Communist Party".

In the 2010s, the CPI was active in Right2Water Ireland and called for a constitutional amendment to enshrine ownership of water in the hands of the Irish people and not the state.