The Dukes (5-3), who shot 51.9 percent from the field (27 of 52), jumped out to a 9-0 lead. James Madison pushed the lead into double figures for good at 28-18 with 4:21 left in the first half.
The Bulldogs (2-8), who have lost six in a row, shot just 35.8 percent (19 of 53) from the floor.
The teams shot a combined 24 free throws, with James Madison making 5 of 8 and The Citadel only 5 of 16.
The Dukes played without junior forward Trevon Flores, who left the team due to personal reasons. Flores was averaging 2.8 points and 2.4 rebounds per game.
Mike Groselle scored 11 to lead the Bulldogs, who posted their lowest point total of the season.