Pakistan captain Misbah-ul-Haq won the toss and chose to bat against Australia in the Boxing Day Test at the MCG.
His counterpart Steven Smith also said he would have batted first on a day that looks useful for batting.
Pakistan, who must win to stay in the series, made one change to their XI, swapping Sohail Khan for Rahat Ali.
The hosts chose an unchanged team from the XI that has won each of the past two home Tests, both day-night affairs. That means there will be more heavy lifting for pacemen Mitchell Starc and Josh Hazlewood in a four-man bowling attack.
The weather in Melbourne is fine and humid, with some chance of showers later in the day.
Australia 1 Matt Renshaw, 2 David Warner, 3 Usman Khawaja, 4 Steven Smith (capt), 5 Peter Handscomb, 6 Nic Maddinson, 7 Matthew Wade (wk), 8 Mitchell Starc, 9 Josh Hazlewood, 10 Nathan Lyon, 11 Jackson Bird
Pakistan 1 Sami Aslam, 2 Azhar Ali, 3 Babar Azam, 4 Younis Khan, 5 Misbah-ul-Haq (capt), 6 Asad Shafiq, 7 Sarfraz Ahmed (wk), 8 Wahab Riaz, 9 Yasir Shah, 10 Mohammad Amir, 11 Sohail Khan