Tarver made his professional debut at the age of 28 on February 18, 1997, with a second-round knockout of Joaquin Garcia at the legendary "Blue Horizon" in Philadelphia.

Tarver won his first 16 fights,14 by knockout, before stepping up his level of competition. After taking most of his first 16 fights in either his native Florida or at the "Blue Horizon", for his 11th fight he met veteran Rocky Gannon in Chester, West Virginia, on August 30, 1998. Tarver knocked out Gannon in the second round.

On February 29, 2000, Tarver fought Ernest Mateen, who had previously fought and lost to James Toney, over whom he proceeded to score a first-round knockout in Las Vegas.

Later that year, Tarver suffered his first loss when he was knocked down in the 11th round by Eric Harding, en route to a unanimous decision on June 23 in Biloxi, Mississippi.

However, he rebounded from this defeat with six straight wins, including a knockout of Harding in round five of their rematch.

On April 26, 2003, Tarver received his first world title shot, when he faced former world champion Montel Griffin for the IBF and WBC world light-heavyweight titles that had been vacated by Roy Jones Jr., who had gone on to beat John Ruiz for the WBA world heavyweight title the previous month. After dropping Griffin in the first and last rounds, Tarver was crowned world Light Heavyweight champion after winning a unanimous decision.