The two sentences will run concurrent. A jury found Mathis guilty in October of those charges plus 51 counts of illegal possession of a slot machine. He received time served for the latter charges.
Judge Kenneth Lester rejected a sentence of two years of house arrest, which was recommended in a presentence investigation.
Mathis remains free on bond. He was one of 57 people arrested in March in the Allied Veterans of the World investigation. Allied Veterans was a nonprofit that operated dozens of Internet cafes, which prosecutors say were illegal gambling operations.
Mathis has appealed the convictions.
Jacksonville attorney Kelly Mathis was sentenced today to six years on a racketeering charge and five years for 51 counts of setting up or conducting a lottery.