Aminu went to Norcross High School and was ranked as one of the top college recruits in the nation from the class of 2008. He was ranked #7 in the nation by Rivals.com and #13 by Scout.com.
Aminu transferred to Norcross between his freshman and sophomore years from Wesleyan School but was ruled ineligible and had to play on Norcross’ jv team his sophomore year. In his junior year, Aminu and teammate Gani Lawal led Norcross to a 30–3 record and a #12 national seed. Aminu averaged 13.7 points and 9.5 rebounds per game in his junior year. He led Norcross to back to back Georgia 5A state titles in 2007 and 2008. He averaged 23.1 points and 11.2 rebounds a game as a senior. Norcross finished 29–2 and ranked #6 in 2008. Aminu was a member of the 2008 McDonald’s All-American Team and played in the Jordan Brand Classic where he had 12 points and 13 rebounds.