Mustafizur began his international career in a twenty overs match against Pakistan on 24 April 2015, where he took the wickets of Shahid Afridi and Mohammad Hafeez, two veteran Pakistani batsmen.
In June, India toured Bangladesh for one Test and three One Day Internationals. Rahman was picked in the ODI squad. In his first match of the series, Rahman gave signs of his potential against the strong Indian batting line-up by taking a five-wicket haul off 9.2 overs in the first match.Bangladesh won the match and Rahman became the tenth bowler in the history of ODIs to take five wickets on debut.In the second ODI, Rahman took another six wickets.This helped him to earn the record of most wickets of any bowler after two ODIs, surpassing the record previously held by Zimbabwe's Brian Vitori.He completed the last ODI with 2 wickets and made history by taking 13 wickets in a three-match ODI series.
The following month, Rahman took 5 wickets in three ODIs to help Bangladesh win the series against South Africa by 2–1. He made his Test debut in the same series versus South Africa where he picked up 4 wickets.
