The purpose of this investigation was to determine the effectiveness of using imagery in eliminating post-rest warm-up decrement (WUD) in the volleyball serve, and to assess whether individual differences in imagery ability mediated any possible reductions in WUD. Thirty-nine State level volleyball players were placed into one of 3 groups, High Imagery, Control, and Low Imagery, based on their scores on the Vividness of Movement Imagery Questionnaire (VMIQ). Players served 15 balls at a designated target area, rested for 10 minutes, and then attempted 5 more serves. During the last 2 minutes of the rest period, the players in the High and Low Imagery groups engaged in imagery of successful serving every 10 seconds, for a total of 12 repetitions. The Control group continued to read a magazine article. To ensure adherence to the imagery instructions, players were evaluated at completion of testing. Results revealed the High Imagery group was significantly better on serving performance post-rest, however there was no significant differences when comparing the mean of the last 3 pre-rest trials with the first post-rest trial. The interaction approached significance (p_= .091) and suggested that the High Imagery group may have benefited from the use of imagery. These findings have implications for the Nacson and Schmidt's (1971) activity-set hypothesis that states that an appropriate task will reduce WUD. It may need to include the effect individual differences, such as imagery ability, may have on the performance of that task.