An orthodox left armspinner who is not a huge turner of the cricket ball, his accuracy and consistency, as well as his ability to exploit rough patches on the pitch, works well at both domestic and elite levels. He bowls flat and tries to control the flow of runs. His batting has also helped Pakistan on some occasions in test matches. In most matches his bowling has had helped Pakistan win but his batting has also helped at times.
Rehman's rise to fame started in 1999 when he took hauls of five and six wickets in successive matches while representing Pakistan Under-19 against South Africa. He was picked for the side even though he only had two first-class outings. His performances in domestic competitions have been notable, especially during the 2006–07 season where he ended up as the highest wicket-taker in the Pentangular Cup including an 11 wickets for champions Habib Bank Limited in the penultimate match of the season.
Rehman signed on as one of the two overseas players for Somerset County Cricket Club in July 2012, after the county had suffered a series of set backs in securing a second overseas signing. After delays over his work permit visa, he played his first match against Nottinghamshire on 7 August. In the last four-day championship match of the 2012 season at the County Ground, Taunton in September, Rehman took a career-best tally of 9–95 against Worcestershire.
On 7 November 2014, Rehman signed a contract to return to Somerset as their overseas player for the entirety of the 2015 season.
In the early years, Rehman's opportunities on the international circuit were limited, partly because of the abundance of spinners in the Pakistani line-up, and partly because he was believed to lack the ability to cause major concern to batsmen in Test matches. Rehman's Test debut was an auspicious one – he took eight wickets at home against South Africa in 2007 – but played only one more Test before being dropped for three years. Upon his return in 2010, he carved a more permanent place for himself as Pakistan opted for a twin-spin attack in Tests along with Saeed Ajmal. He showed that he deserved a place by reaching the 50-wicket mark in only his 11th Test.
In January 2012, Rehman took his first five-wicket haul in a Test, taking 6/25 as Pakistan bowled England out for 72 in the second innings of the second Test of their series in the United Arab Emirates. He took another five-wicket haul (5/40) in England's first innings of the Third Test in Dubai, as Pakistan won the series 3–0.
He bowled three consecutive beamers in an ODI match against Bangladesh on March 4, 2014.