He played college football for the Penn State Nittany Lions, earning unanimous All-American honors.

[1] He worked to become an NFL-caliber player because he thought it would help him raise the money to reunite with his mother, Rachel Keita, and bring her to the United States after not having seen her for more than twelve years.

He was instrumental in helping the Nittany Lions finish 11–1, winning the Big Ten championship and the Orange Bowl that season.

[5][6][7] He led the Big Ten with 11 sacks (tied for eighth nationally) and 17 tackles for loss and earned numerous accolades for his play.

Hali received the Robert B. Mitinger Award, which is given to the Nittany Lion football player who best personifies courage, character, and social responsibility.

[10] Hali entered the 2006 NFL draft ranked as the third-best defensive end behind Mario Williams and Kamerion Wimbley.

[14] On 31 July 2006, Hali was excused from the Chiefs two-a-day practices at training camp in River Falls, Wisconsin and flew back to his home in Teaneck, New Jersey to be sworn in as a permanent citizen of the United States.

[15] On 28 September 2006, Hali's mother Rachel arrived in Kansas City, Missouri and lived with Tamba on a one-year visa.

Hali's transformation from an undersized 4–3 DE to a 3–4 OLB was an amazing one considering his time in college as a defensive tackle.

[22] He finished the 2009 season with 8.5 sacks, 63 total tackles, one pass defensed, four forced fumbles, and scored a safety.

[25] Hali finished the season with an AFC-leading 14.5 sacks, leading to his first invitation to the Pro Bowl, which he declined citing personal reasons.

[26][27] Chiefs' general manager Scott Pioli made the signing of Hali to a long-term deal his top priority that off-season.

[51] In 2017, Hali started the 2017 season on the physically unable to perform list due to an undisclosed injury that kept him out all of training camp and the preseason.

[53] He was moved to the active roster on 4 November 2017, prior to the team's Week 9 game against the Dallas Cowboys.

[56] He finished his tenure with the Chiefs second in team history in sacks behind only Hall of Fame linebacker Derrick Thomas.

[15] Following his rookie year, Hali began training in Brazilian jiu-jitsu under the instruction of Rener Gracie and was promoted to purple belt in November 2017.