Born in Nkawkaw, Ghana, after playing 70 games for Dutch giants Feyenoord Rotterdam, Boateng completed a £220,000 move to Coventry City in 1998. Under the management of Gordon Strachan he proved himself to be a solid defensive midfielder, helping the attacking Dublin-Huckerby Coventry side of 1998 finish eleventh in the Premier League and enjoy mid table stability. He is still fondly remembered by Sky Blues fans as being responsible for breaking one of Coventry’s longstanding hoodoo’s-victory at Villa Park: Boateng scored twice in the 4–1 win over Aston Villa at Villa Park on 27 February 1999, ending Coventry’s 63-year-long wait for a league win at the ground.
The next season Boateng transferred to Aston Villa for £4.5 million. He proceeded to play 131 matches for Villa, including an FA Cup final defeat against Chelsea in 2000. The tough-tackling central midfielder then fell out with manager Graham Taylor in the 2001–02 season. After a move to Liverpool collapsed due to demands from agents, and in spite of interest from Fulham, that summer Boateng completed a £5 million move to Middlesbrough.
Boateng made his full debut on the first day of the 2002–03 season away to Southampton in an uneventful game that finished 0–0. Occupying the defensive midfield position, he became the solid platform upon which Middlesbrough built their attack. He recovered from an ankle operation in the summer of 2003 to be fit for the start of the 2003–04 season. That season, he was part of the Middlesbrough team which lifted the League Cup for the first time.
In the 2004–05 season, he scored his first goal for Middlesbrough in a 4–0 win at Blackburn Rovers on 16 October 2004. However, he was injured for eight weeks with a broken toe; during this period, Middlesbrough dropped from fourth down to ninth in the league. He did recover in time to help Middlesbrough obtain the results they needed for qualification for the UEFA Cup. In a poll on the official Boro website, fans voted him the player most missed due to injury in the 2004–05 season. He started for Middlesbrough in the 2006 UEFA Cup Final.
In June 2006 he signed a new three-year contract with Middlesbrough. He was announced as the new club captain on 21 July 2006, replacing Gareth Southgate, who had been promoted to manager. On 10 March 2007, he scored in an FA Cup tie against league leaders Manchester United, his first goal in the tournament since 1999 when he scored for Coventry against Macclesfield Town.
On 22 January 2008, Boateng had his captaincy rescinded by Gareth Southgate. Southgate cited his desire for Boateng to “concentrate on his game”. He was replaced as captain by Emanuel Pogatetz.
Hull City announced on 10 July 2008 that Boateng had agreed to sign a contract with them. The move was completed on 16 July, after the completion of a medical. On 6 February 2010, Boateng scored his first career goal for Hull City in a 2–1 win over Manchester City, their first win since November 2009.
Boateng’s contract with Hull City came to an end following their relegation from the Premier League in 2010. He was confirmed as having left the club along with fellow former Dutch national team-mate Jan Vennegoor of Hesselink.
After holding talks with Celtic and West Bromwich Albion he joined Greek side Skoda Xanthi on a two-year deal.
On 27 July 2011, it was announced that Boateng had joined Nottingham Forest, on a one-year deal.
Boateng scored his first goal for Nottingham Forest in dramatic fashion, scoring in the 94th minute to grab Forest a point against Leicester City. At the end of June 2012 he left the club.
On 15 November 2012 he arrived at Kuala Lumpur International Airport to sign a contract with T-Team. Four days later he signed a one-year contract, linking him again with former Hull City team-mate and Republic of Ireland international Caleb Folan.
Although born in Ghana, Boateng chose to represent Netherlands at international level, earning four caps in total for Oranje. Boateng made his international début for the Netherlands in a 1–1 draw with Denmark in November 2001.
Boateng has made no secret of his desire to enter football management once his playing career ends. After leaving Nottingham Forest F.C in 2012 he completed his coaching badges in Ireland and in an interview with the Daily Mail he revealed that his dream job in management would be at his former club Aston Villa F.C saying “They have the training ground, the fan base, great stadium. And I love the ground.”.
On 2014,Boateng was unveiled as Kelantan FA new head coach to replace Steve Darby who has been shown the exit door after a disappointing 0-4 lose to Sime Darby F.C.. On 6 May 2014, Kelantan FA come back from 3-0 down to draw 3-3 with Felda United F.C. in first leg of Malaysia FA Cup semi final in Boateng’s first game as head coach. After Kelantan FA knocked out of the Malaysia Cup by Kedah FA with 3-4 aggregate,he apologized to the fan and there were report saying that he will not continued his job as Kelantan FA head coach next season.