Mahmudullah is a talented allrounder capable of bowling tidy offspin and giving the cricket ball a good hit. Having played the bulk of his first-class career for Dhaka Division he was called up to the Bangladesh A side. Good displays with the A side earned Mahmudullah a maiden ODI cap during Bangladesh's tour of Sri Lanka in July 2007, during which he hit 36 and took 2 for 28 from five overs. He finished the 2008-09 National Cricket League first-class season as the second-highest run getter with 710 runs.