On 15 February 2005 the campaign began in earnest when it was announced that polling would take place on 11 March. Eight candidates contested the vacant seat, with victory going to the Independent candidate, Catherine Murphy. Her 23.6% share of the first-preference vote was the lowest recorded at any by-election since Patrick Kinane won the Tipperary by-election in October 1947 with a 21.4% share.
As a result of her election, Kildare North was the only constituency in the Republic of Ireland that did not have a TD from one of the government parties of Fianna Fáil or the Progressive Democrats. Murphy also went into the record books as County Kildare's first ever female member of Dáil Éireann.
On the same day, a by-election took place in Meath.