The Fourth Amendment altered Article 16 which deals with elections to Dáil Éireann (the house of representatives of the Oireachtas).

It was submitted to a referendum on the same day as the Fifth Amendment, which removed from the constitution reference to the "special position" of the Catholic Church and recognition of certain other named denominations.

[2] On 28 June 1972, the Minister for Foreign Affairs Patrick Hillery moved the Fourth Amendment of the Constitution Bill 1972 on behalf of the Fianna Fáil government.

A 20-year-old student, represented by Seán MacBride, asked the High Court to postpone the election to vindicate his right to vote.

The later Ninth Amendment passed in 1984 altered the text of Article 16.1.2° in a manner which would permit legislation to include certain people who are not citizens to be added to the register for elections to Dáil Éireann.