Martins is known for his exceptional pace, powerful shots and acrobatic goal celebrations. Although relatively short, Martins has a good leap and it has been reported that he used to be very good at the long jump and high jump as well as gymnastics Martins is left footed; however, since joining Newcastle he has shown that he is also more than capable of scoring with both feet and his head.

Martins has two brothers who also play football. His elder brother, Oladipupo Olarotini Martins, is on the books of Serbian side FK Partizan, whilst his younger brother John Abiola Martins plays football in Nigeria.

In 2000, Martins was involved in the youth setup at AC Reggiana, and moved into Inter's youth squad following season in a €750,000 deal. With the youth squad he scored 23 goals that season, helping them win the Italian Under-18 title.

He became a part of the Inter first team in 2002 making his debut against Parma in December of that year. However he did not fully break into the first team until the following season. It was in 2003 that he fully made his mark with the club in the UEFA Champions League, first scoring a crucial goal against Bayer 04 Leverkusen to secure Inter's place in the quarter finals of the competition. Martins then scored another goal in the semi-final of the competition against Milanese rivals AC Milan, although Inter were eventually defeated on the away goals rule.

Martins signed a long-term contract with Inter in 2005 which ran until 2010 and was worth around €2.5 million annually.His good form for Inter continued and he was called to play in the 2006 African Nations Cup for Nigeria.

Although he had some success with Inter, scoring 28 goals for the club in 88 league games as well as 11 goals in European competitions, the young Nigerian was sold in August 2006. This was due to Inter bringing in two new strikers; first Argentinian Hernán Crespo was brought in on loan from Chelsea and then the Bosnian Swede Zlatan Ibrahimović was bought by Inter from recently relegated Juventus.

During his time at Inter he picked up an accolade at the 2004 Italian Media Awards held in Rome. He was awarded 'Most Entertaining Interviewee,' fighting off stiff competition from Taribo West and Ron Atkinson.

With Martins handing in a transfer request in August 2006, a number of English clubs were alerted to his availability. From the onset, Newcastle were thought to be the front runners and it was no surprise when on August 24, 2006 Martins completed his move to Newcastle United from Inter for £10.1 million (€15 million), signing a five year deal. He was paraded in front of the Geordie fans before their UEFA cup tie against FK Ventspils, it was later confirmed he would be taking the famous number 9 shirt, replacing club-record goalscorer Alan Shearer who had occupied it for the previous 10 years.

Martins made his debut on August 27, in the 2-0 defeat to Aston Villa, in which he was stretchered off with a knee injury. It turned out that Martins suffered a severe dead leg and internal bleeding. His unremarkable first few appearances for Newcastle caused manager Glenn Roeder to speak out in his defence.

However, on Sunday 17 September 2006, Martins scored his first goal for Newcastle. It was the second goal in a 2-0 victory over West Ham United at Upton Park, and from there his goalscoring form began to improve steadily.

Reports on January 11, 2007 indicated that Chelsea were considering making an offer for Martins services after his impressive form. These reports were later rubbished by Glenn Roeder and Martins himself.

On January 14, 2007 in a 2-3 away win against Tottenham Hotspur Martins' 20 yard shot flew into the net. This strike was clocked by Sky Sports at a speed of 84 mph (135 km/h), making it the ninth hardest shot ever recorded in football.This was his tenth goal for Newcastle. Martins ended his first season on Tyneside with 17 goals in 46 games.

Martins has scored 11 goals in 14