Polling was delayed until 19 June 2004 in County Roscommon, due to the sudden death of Councillor Gerry Donnelly.

[3] Labour's share of the vote remained static at 11% while Fine Gael dropped 1%.

Major gains were made by Sinn Féin which managed to double the number of seats it held, mainly at the expense of Fianna Fáil.

These were the first elections since the Local Government Act 2001 modernised council structures and abolished the dual mandate.

According to the different franchises in Irish law, all residents were eligible to vote in the local elections, all EU citizens were eligible to vote in the European elections, and the referendum was confined to Irish citizens.