The master batter had a few nervous moments but broke the shackles after lunch to post his half-century to take the hosts to 8-183 at tea on day one of the first Test in Darwin on Thursday.
Smith, who was unbeaten on 67, has not scored a Test century against Bangladesh, the only one of the nine Test-playing nations he has played against where he has not achieved the milestone.
The rest of the Australian batters struggled as Bangladesh pace trio Taskin Ahmed, Ebadot Hossain and Hasan Mahmud bowled superbly.
Ebadot cleaned up Alex Carey (19) after lunch and Taskin castled Beau Webster (12) with an absolute beauty. Pat Cummins (nine) and Mitchell Starc (one) both nicked off to Mahmud before tea.
Smith made a statement when he launched veteran spinner Taijal Islam over the ropes and then through the covers in his first over of left-arm spin.
He had little support in conditions that suited the seamers.
Earlier the battles of Jake Weatherald and Marnus Labuschagne in Test cricket continued as Bangladesh struck early blows to have the hosts 4-74 at lunch after Cummins won the toss and elected to bat first.
Weatherald had an opportunity to enhance his chances of staying in the top order in front of a partisan crowd in Darwin, the city of his birth, but was unable to make the most of a start at Marrara Stadium.
It was no surprise when the 31-year-old edged impressive paceman Mahmud on the cusp of drinks to bring an end to a scratchy 23 off 37 deliveries.
Opening partner Travis Head (22) followed soon after, chopping on to Hasan when he went around the wicket.
Ebadot had Labuschagne (1) edging to captain Najmul Hossain Shanto with an indecisive poke as his drought without scoring a Test century extended to 37 innings.
Ebadot should have claimed the prize scalp of Smith on two when he was dropped by Tanzid Hasan at third slip.
Bangladesh then lost a second review when Smith was given not out on seven after Ebadot was convinced he'd nicked one.
A horror shot by allrounder Cameron Green (13) on the stroke of lunch went straight to mid-wicket to put Bangladesh on top.
Weatherald was unconvincing early after making an adjustment to his set-up at the crease.
Mahmud, 26, found a good length and movement to have Weatherald playing and missing.
Weatherald scored just 201 runs at at average of 22.3 in last summer's Ashes and had a technical issue, with his head positioned outside off stump and a tendency to fall over even further.
He adjusted that so his head was more aligned above the stumps, but his wickets were also exposed on occasions due to his changed stance.
An off-drive for four off Mahmud was a moment of promise, followed by a cracking cover drive, but the next ill-advised flash proved his undoing.
Cummins had no hesitation in opting to bat when he won the toss, but the decision suited Bangladesh captain Shanto, who liked the look of the surface. His bowling attack delivered.
The Test is the first played at the venue since 2004 and just the third in Darwin history after Bangladesh were the first visiting side in 2003.
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