As a sophomore in 1996, Green compiled a team-leading 917 yards on 155 carries and seven touchdowns, despite a turf toe injury. Green had a career-high 214 yards against Iowa State University that season.

Green played in a bowl game each season he was at Nebraska. In the 1996 Fiesta Bowl, he rushed for 68 yards and one touchdown. In the 1996 Orange Bowl (played at the end of the year), he rushed for 52 yards, and in the 1998 Orange Bowl, he rushed for 206 yards and two touchdowns.

As a junior, Green garnered All-Big 12 Conference recognition and was named second-team All-America by the Associated Press and The Sporting News as Nebraska again captured the national championship. He was a finalist for the Doak Walker Award, the annual honor for college football’s top running back, in 1997. During that campaign he carried the ball 278 times for 1,877 yards (6.8 avg.) and 22 touchdowns (a school record for juniors). He posted 12 consecutive 100-yard games, including three contests with over 200 yards (he also had 99 yards on nine carries in the opener against Akron).

During his collegiate career, Green compiled 3,880 rushing yards and 42 touchdowns, both totals good for second place on the Cornhuskers’ all-time list. He also posted 300 receiving yards and three touchdowns on 35 catches. One of Green’s best collegiate performances came on January 2, 1998, in the Orange Bowl. He rushed for an Orange Bowl record 206 yards and two touchdowns in Nebraska’s 42–17 victory over #3 Tennessee, breaking the previous 20-year-old record of 205 yards held by Arkansas running back Roland Sales. Green was also named the 1998 Orange Bowl MVP. The performance marked the Cornhuskers’ record-setting third national championship in four years, due partially to a requirement that the champion of the Big Ten Conference (#1 Michigan that season) play the winner of the Pac-12 Conference in the Rose Bowl.

Green was drafted in the third round (76th overall) of the 1998 NFL Draft by the Seattle Seahawks. Although Green produced a high rushing average (6.0 in 1998 and 4.6 in 1999) he had difficulty earning significant playing time behind established veteran Ricky Watters.

In 2000, Green was traded along with a fifth round draft pick to the Green Bay Packers for Fred Vinson and a sixth round pick. He was selected to the NFL Pro Bowl from 2001 to 2004 and broke several franchise records. From the time he joined the Packers in 2000 up through the end of the 2004 season, Green gained more yards from scrimmage (9,036) and rushing yards (6,848) than any other NFL player. In 2003, he had his best year as a professional and set the Green Bay franchise record by running for 1,883 yards in the regular season. That year, he became the first and only player in NFL history to record at least 1,850 rushing yards, average 5.0 yards per carry, score 20 touchdowns and catch 50 passes in one season. He threw a touchdown pass on October 17, 2004 vs. the Detroit Lions. During his time with the Packers, Green became one of two players in NFL history to have two touchdown runs of 90 or more yards (Bo Jackson is the other). Despite his injury-shortened 2005 season, the Packers re-signed Green to a one-year, $2 million contract, with an extra $3 million in incentives. After the 2006 season he became a free agent.

Green was named after former NFL wide receiver and current broadcaster Ahmad Rashād. In 2006, Green played a small role in the film Big Stan as the prisoner Diamond King.

On March 4, 2007 Green signed a four-year, $23 million deal with the Houston Texans. He was reunited with his former head coach and former Texans’ assistant head coach Mike Sherman along with former Packers running back Samkon Gado. He was asked to handle the bulk of the load at running back after a 2006 season in which the Texans used a “running back by committee” approach.

On February 10, 2009, Green was released by the Texans.

Ahman Green officially re-signed with the Green Bay Packers on October 21, 2009, after the Packers placed running back DeShawn Wynn on injured reserve. With his former number, 30, taken by fullback John Kuhn, Green chose to wear No. 34 in honor of former Chicago Bears running back Walter Payton. On November 8, 2009 Green broke Jim Taylor’s record to become the all-time leading rusher in Packer history.

On February 7, 2011, the Montreal Alouettes of the Canadian Football League announced they signed Green to a tryout contract, signing Green to an official contract in March of that year. Green was released on Sunday of training camp on June 5, 2011 after arriving with an injured hamstring.

Green announced his permanent retirement from football in August 2011.

On September 21, 2012, Green was inducted into the University Of Nebraska Football Hall of Fame and was inducted into the Green Bay Packers Football Hall of Fame on July 19, 2014.

On June 26, 2017, Green was arrested on suspicion of child abuse.

In February 2020, Green was named as the first head coach of Lakeland University’s new varsity eSports team.