Diogu was selected 9th overall in the first round of the 2005 NBA Draft by the Golden State Warriors. He attended Arizona State University, where he excelled on the team under head coach Rob Evans. He garnered several honors, both in the Pac-10 and nationally.
Many in the public speculated that Diogu would enter the draft after playing for his third season with Arizona State. On June 21st, he made the decision to enter the draft. Earlier that year, his father had told the media about this decision, but Diogu, speaking for himself, denied making any such decision. It was revealed afterwards that Diogu preferred to return to school, but his parents encouraged him to go pro.
Ike Diogu stands at 6 feet, 8 inches (2.03 m) tall, which is considered undersized for an NBA power forward, but is apparently not a concern for the Warriors. His parents are natives of Nigeria and moved to Buffalo, New York in 1980 to pursue further education.
On December 23rd, 2005, Ike recorded a professional career-best 27 points on 13-15 shooting.