A prominent figure in the Bangladeshi cricket circuit, Mahmudullah is a professional cricketer of the Bangladesh national team, who leads the current T20I team. He has played First-class and List A cricket for Dhaka Division and has represented Bangladesh in all forms of the game. 

The all-rounder is a lower or middle-order batsman and an off-spin bowler. He is prominent for his ability to finish a close limited over game. He is the first Bangladeshi to score a World Cup hundred.

Mahmudullah was called up for Bangladesh's ODI squad for the three matches against Sri Lanka in Bangladesh's tour of the country in July 2007. He made his debut on the tour, in the third ODI, where he was Bangladesh's second-highest scorer (with 36 runs) and also took two wickets, in the match, which Sri Lanka won by 39 runs. 

Although Mahmudullah scored a Test century batting at number eight against New Zealand, the selection committee preferred not to promote him up the order due to a perceived weakness against fast bowling despite the number four spot having no permanent occupant. After having cemented his place in the squad, Mahmudullah was included in  Bangladesh's 15-man squad for the 2011 ICC Cricket World Cup. 

On September 20, Mahmudullah was named as the vice-captain of the national team taking over Tamim Iqbal after the previous captain and head coach were sacked. His career-defining moment came on March 9, 2015, in the ICC Cricket World Cup against England, where he became the first  Bangladeshi batsman in World Cup history to score a century. Bangladesh went on to win the match and qualified for the quarterfinals. In the next match against New Zealand, he scored another century but this time New Zealand won the game by three wickets. In 6 matches of the World Cup, Mahmudullan amassed 365 runs making himself the star performer for the Tigers.

In the 2017 Champions Trophy, Mahmudullah found himself on another record sheet when he along with Shakib Al Hasan set the record for the highest fifth-wicket partnership in Champions Trophy history and also the highest partnership for any wicket in Bangladesh’s history. His century in the crucial semi-final booked a berth in the semis for the Tigers.

After a poor display in the longer formats, he was asked by the Bangladesh Cricket Board to mainly focus on white-ball cricket and his central contract was revoked to just white-ball contract. In the recently concluded Bangabandhu Cup, he was the skipper of Gemcon Khulna and won the inaugural edition of the tournament.

Dropped from the squad for red-ball cricket, Mahmudullah made a comeback in the ODI squad against West Indies in January 2021. Bangladesh white washed West Indies 3-0 after some splendid all-round performance by Mahmudullah. 

Being a leading figure in the Bangladeshi cricket domain for over ten years, Mahmudullah’s task would be to mould the youngsters and prove a factor in the rebuilding phase of the Tigers.

(As of March 2021)