Ballistic resistance training involves explosive movements against resistance at the fastest velocity possible. This study examined the effect of a ballistic resistance training program on baseball throwing and base running speed. Eighteen National League baseball players from two teams took part in the 10-week training study in conjunction with their normal preseason baseball training. Nine subjects from one team served as the control group and did not take part in any form of ballistic resistance training. Nine from the other team served as the training group and performed explosive squat jumps and bench throws with a light load that maximized power output (approx. 30–50% 1-RM). Both groups also participated in normal baseball training. Pre- and posttraining throwing speed and average running speed were recorded. The training group significantly improved throwing speed by 2.0 ± 1.5% (p ≤ 0.05); no change was recorded for the control group. Both groups increased running speed, but the increases were significantly greater for the training group. It is concluded that ballistic resistance training can increase performance in baseball throwing and base running, thus such training methods should be incorporated in baseball training programs.