Australia coach Ewen McKenzie resigned following their 29-28 defeat by New Zealand in Brisbane.
McKenzie oversaw defeats in Australia's past three games and leaves less than a year before the World Cup.
The 49-year-old was also under pressure because of a row over offensive text messages back Kurtley Beale allegedly sent about a team official in June.
"My intention was to resign win, lose or draw," McKenzie said. "I've been unhappy with a bunch of things."
McKenzie, who took over from Robbie Deans 15 months ago, added: "The easiest thing for me is to exit stage left.
"I'll leave you guys to speculate or ponder, I'll write a chapter in my book."
Australian Rugby Union (ARU) chief executive Bill Pulver said: "I did not ask Ewen to resign, but understand his decision."
Australia take on Wales, France, Ireland and England in November.
The Wallabies are also in the same group as Wales and hosts England for the 2015 World Cup.
McKenzie won 11 of his 22 Tests in charge, including a seven-match winning streak.
But defeats by South Africa and Argentina in the Rugby Championship were followed by Saturday's loss to the All Blacks, who scored a last-minute converted try.
|Australia's past five games|
|6 September: Australia 24-23 South Africa|
|13 September: Australia 32-25 Argentina|
|27 September: South Africa 28-10 Australia|
|4 October: Argentina 21-17 Australia|
|18 October: Australia 28-29 New Zealand|
"Ewen is a world-class coach and a world-class individual who has been committed to playing entertaining rugby for our fans since he started in the role," Pulver added.
Pulver hopes to appoint a new coach before Friday, when the Wallabies depart for their northern hemisphere tour.
Former South Africa coach Jake White, and Michael Cheika - who led New South Wales Waratahs to the Super Rugby title this year - are likely to be among the candidates.
Pulver said he would be seeking "a coach who can lead us to victory in next year's Rugby World Cup, represents rugby's core values, has the support of the playing group and is available".
Ex-Australia prop McKenzie was assistant coach of the victorious Wallabies for the 2001 Lions tour.
He was also part of the Australia set-up that lost 20-17 to England in a dramatic 2003 World Cup final.