[13][14] Born in Owerri, Imo State,[2] Kanu began his career at local side Federation Works before moving to Iwuanyanwu Nationale.

After a notable performance in Nigeria's victorious U-17 World Championship campaign, he was signed by Dutch giants AFC Ajax in 1993 for an undisclosed fee.

That summer he captained the Nigeria national team that won gold at the Olympics, and scored two late goals in the semi-finals against powerhouses Brazil to overturn a 2–3 scoreline into a 4–3 win in extra time.

[18] However, soon after returning from the Olympics, Kanu underwent a medical examination at Inter, which revealed a serious heart defect, and it was believed by doctors that his career was over.

In interviews, Kanu frequently cites his faith as a Christian,[21] and has often mentioned this trying time of his career as an occasion when he prayed to God.

With the score 1–1 and ten minutes to go, the Sheffield United goalkeeper Alan Kelly kicked the ball out of touch so that treatment could be given to Lee Morris.

In the 1999–2000 season he scored 17 times in 50 matches for the Gunners, including a hat-trick in fifteen minutes against Chelsea in October 1999 to turn a 2–0 deficit into a 3–2 victory.

[31] Along with other famous players, such as Henry and Robert Pires, Kanu is a member of the "Invincibles", the Arsenal side that finished the 2003–04 season of the Premier League undefeated.

At the end of the match, Kanu joined the rest of the Arsenal side in hoisting the retired Dutchman on their shoulders as fans gave him a standing ovation.

[citation needed] In a match against Middlesbrough on 14 November 2004, Kanu was guilty of an incredible miss in injury time, with Albion 2–1 down.

[37] Nevertheless, the 2004–05 season was ultimately a memorable one for West Bromwich Albion, as they became the first club to avoid relegation from the Premier League after being bottom of the table at Christmas.

[citation needed] Kanu was a free agent following his departure from West Brom, and he signed for Portsmouth on a one-year deal shortly before the start of the 2006–07 season.

[41] Pompey had undergone a revival in the second half of the previous campaign, following the return of Harry Redknapp as manager, avoiding relegation by four points after being in serious danger at the turn of the year.

Kanu made his debut for Portsmouth as a substitute against Blackburn Rovers on 19 August 2006, the opening day of the 2006–07 Premier League season.

On 9 July 2012, it was announced that Kanu and Aaron Mokoena were expected to leave the club after failing to attend the first day back at pre-season training.

Earlier on at the start of his career, Kanu was instrumental in Nigeria's overall success at the 1993 FIFA U-17 World Championship in Japan and their subsequent 2–1 victory over Ghana in the final.

Despite his physical strength, slender frame, and large stature of 1.97 m (6 ft 6 in), Kanu was a talented player, who was quick and elegant in possession, and who possessed an excellent touch on the ball and nimble footwork; he was also highly regarded in the media for his technical skills, dribbling ability, and close control, as well as his flair and use of feints, which made him an unpredictable player on the pitch.

He was also an intelligent player, who possessed good vision and movement, as well as being a good passer, who had the ability to read the game and an eye for the final ball, which – along with his timing and finishing ability – allowed him both to score and create goals; however, he also lacked significant pace, and drew criticism at times in the media over his work-rate, "languid" playing style, and occasional tendency to miss easy goalscoring opportunities.

[69][74] Although his height made him a strong presence in the air, he was more adept at scoring with his feet than with his head, despite his size, although he improved upon his aerial game in his later career.

[82] However, despite being a gifted player, he was also known for being inconsistent,[83] and his congenital heart defect is thought to have had a negative impact on his career and fitness, although he was able to improve his stamina following corrective surgery through his training.

[85] Kanu is a native of Abia State, southeast Nigeria,[86][87] and a member of the Aro sub-group of the Igbo ethnic group.

[65] Kanu was born with a congenital heart defect, which impeded his aortic valve from closing properly; it was discovered and operated on in 1996.