He made his full international debut for Nigeria at the 2006 African Cup of Nations, scoring once in three appearances as his side were eliminated in the semi-finals.

On 4 October 2007, Obinna was involved in a car accident on his way home from training in which he swerved away from a vehicle that had tried to overtake him around a bend.

[6] In the summer of 2008, Obinna moved back to Inter Milan for a €1.2 million transfer fee in a three-year contract.

[7] English club Everton attempted to immediately sign him on loan, but were unable to secure a work permit for the player.

[13] He scored his first goal for West Ham in a 2–1 win against Sunderland in the third round of the League Cup at the Stadium of Light on 21 September 2010.

[15] He continued the fine form with four assists in a 4–0 win against Manchester United on 30 November 2010, automatically booking a first League Cup semi-final for 20 years.

[17] On 30 January, Obinna scored a hat-trick in a FA Cup 4th round tie against Nottingham Forest, leading West Ham to a 3–2 victory.

[29] Nigeria were drawn against Ivory Coast who they beat 2–0, with Obinna scoring a penalty and setting up Peter Odemwingie for the other goal.