Prior to his ban and prison sentence, he had been a regular Test and ODI left-handed opening batsman. He made his Test debut on 3 September 2003 in the third Test against Bangladesh, and a year later, made his ODI debut against West Indies on 22 September 2004. He was appointed captain of the Pakistan Test squad on 16 July 2010.
On 29 August 2010, he was implicated in allegations of spot-fixing. On 31 August 2010, he was stripped of the Pakistan captaincy, and removed from the ODI Squad pending criminal proceedings. He was banned from playing cricket for ten years, of which five years was a suspended sentence. In November 2011, he was convicted and jailed for 30 months for conspiracy charges relating to the spot-fixing, along with Mohammad Amir and Mohammad Asif. On June 21, 2012, he was released from jail.
In August 2015, bans on Butt and fellow conspirators Mohammad Amir and Mohammad Asif were lifted by the International Cricket Council, allowing them to return to all forms of cricket from September 2, 2015.
Butt started in the Under-17s and quickly progressed through Under-19 level, although at that time he was much younger than the age limits suggest, making his senior debut for Lahore Whites in 2000 aged only 15. His talent was noticed immediately, which led to him being given a place in the Pakistan A team against England soon after. However, instead of rushing straight for the limelight of international cricket, he got his head down and consolidated by playing consistently for his region and the youth teams, until the Pakistan selectors finally drafted him in 2003.
After his debut, Butt was dropped, and he struggled to regain his place due to some stiff competition for the openers' spots. He returned for the Champions' Trophy in 2004 and scored his first fifty for Pakistan in the Paktel Cup against Sri Lanka. In the ODI against India on 13 November 2004, as Pakistan chased down 292, he formed partnerships first with Shoaib Malik, putting on 113, and subsequently with Inzamam-Ul-Haq. Despite having retired for seven overs due to severe cramp, he returned to steer Pakistan home, finishing on 108 not out.
Yet 2005 saw little improvement, and doubts circulated about his defensive technique, causing him to be shuffled in and out of the side. But things started looking up again during the winter Test series against England, in which he scored a century and two fifties, with a more cautious attitude to his innings building than he had previously shown.
On 17 July 2010, the Pakistan Cricket Board appointed Butt as captain of the Pakistani Test squad in place of Shahid Afridi, who announced his retirement from Test cricket after Pakistan lost the first test match against Australia. He became the 28th captain of the Pakistani Test team and the fifth to lead them since January 2009.
On 23 July 2010, Salman Butt led Pakistan to victory against Australia in his first appearance as Pakistan's test team captain.
In August 2010, Butt and two other players, Mohammad Amir and Mohammad Asif, were among those named by a News of the World sting where undercover reporters paid an agent loosely affiliated with several players on Pakistan's squad a bribe in return for detailed information on when no-balls would be bowled.
Butt, Amir, and Asif were dropped from the Pakistan team for the limited-over series (two Twenty20 games, and five ODI games). However, on 2 September 2010, after the warm-up List A game between Pakistan and Somerset, the International Cricket Council announced that they had suspended Asif, Amir and Butt under the provisions of the ICC's Anti-Corruption Code. The statement from the ICC stated that the three players were charged "under various offences under Article 2 of the ICC Anti-Corruption Code for Players and Player Support Personnel relating to alleged irregular behaviour during, and in relation to, the fourth Test between England and Pakistan at Lord's last month".
Later it became known that Butt and the other two players implicated in the scandal were in possession of bills with the same serial numbers as those the reporter had paid Majeed earlier. Butt was provisionally suspended from playing International Cricket due to the fact that the ICC wanted his name cleared before he resumed playing cricket. In late September, Butt filed an appeal to the ICC asking them to lift his temporary suspension. After Mohammad Asif had dropped his appeal against the charges so that he could understand the charges filed against him, Butt said he was determined to prove his innocence and that his appeal was going to go ahead.
In an interview with the Associated Press, Butt stated "I do not want to comment on The News of the World because everybody knows what kind of paper it is. Everybody knows about its reputation across the world." He also stated that he was linked to Mazhar Majeed as a player agent but not in any spot-fixing. He also stated that the video can easily be edited and modified and manipulated. One day before the hearing, Butt continued to state his innocence. The tribunal announced that a verdict on the decision had been deferred to 5 February 2011 and that the ICC also stated that the tribunal would rule on charges pertaining to the third Test match between England and Pakistan. Butt was the only player before the tribunal to face these additional charges.
On 5 February 2011, the three-man tribunal delivered its verdict. One charge was dismissed against Butt from the third Test match (batting out a maiden over), but the other charges (failing to report an advance from the third Test match and ordering Asif and Amir to bowl no-balls in the fourth Test) were proved, and Butt was banned from the sport of cricket for ten years, five of which were suspended should he not commit any further offences and participate in a Pakistani Cricket Board anti-corruption program.
In January 2016,PCB allowed Butt to play in the National One Day Cup, in which he played for WAPDA and scored 536 in 7 matches at an average of 107, ending up one of the leading run-scorers in the tournament. He was the man of the match in the final of the 2016–17 Quaid-e-Azam Trophy, scoring a century in both innings. WAPDA won the title.
An accumulator, Butt works hard for his runs, not indulging in too many big hits; his statistics show the low number of 19 international sixes to date (1 September 2010) of which he's scored 10 in Twenty20 cricket, 7 in One-Day Internationals and only six in Test cricket. He scores a lot of his runs between backward point and extra cover. He uses his superb wrist work to angle the bat, placing the ball into gaps using the pace of the ball to his advantage; a very good technique for ODIs where it is best to keep the scoreboard ticking all the time. He also has the ability to cut the ball very fine down to third man if there are no slips, especially against spin bowlers, as he showed to great effect in his above-mentioned innings of 108 not out. These are his specialties, but he has large range of shots. However, many commentators have expressed that his defensive technique has flaws, and that he is prone to playing at balls outside off-stump which should be left.