It was triggered by the presumed drowning death of the Prime Minister and Liberal Party MP Harold Holt on 17 December 1967.

On 15 January 1968, Speaker William Aston stated that there was conclusive evidence that Holt had died, and that a writ would be issued for the by-election.

The Australian Labor Party nominated David Bennett, a research officer with the Australian Council for Educational Research, whilst the Democratic Labor Party, who had received 11.56% of the vote at the November 1966 election in the seat, opted not to contest the election.

The other two candidates were Dr Leonard Webber for the Australia Reform Movement, and a Sydney journalist, Frank Courtis.

[1] Gorton won the by-election for the Liberals with an increased primary vote.