Physical educators continually search of new activities to incorporate into their classes. Cup stacking is a relatively new activity that has been highly promoted at many of the state, regional and national conventions for physical educators. "In the exciting sport of cup stacking, students stack and unstack 12 specially designed plastic cups (Speed Stacks) in predetermined sequences and compete for time." (Speed Stacks, Inc., 2001) The promoters claim participation in this activity will result in many benefits, one of which is improved hand-eye coordination. Although there is much anecdotal support for these claims, limited empirical evidence exists for these claims. The purpose of this study was to empirically examine the influence of a cup stacking instructional unit on the hand-eye coordination of children. Participants (N=104) consisted of three grade level groups (first/second grades, third grade and fourth grade). Within each grade level participants were randomly assigned to either an experimental or a control group. The experimental groups received a three-week instructional unit following the lesson plans provided by Speed Stacks. The control groups received the standard physical education curriculum. All instruction was provided by the school's certified physical educator. All participants completed pretests and posttests on three tasks designed to measure hand-eye coordination: 1) placing 24 pennies in a cup using both hands as fast as possible (two-hand penny); 2) placing 24 pennies in a cup using only the non-dominant hand as fast as possible (one-hand penny); 3) placing 25 pegs in a pegboard as fast as possible. For each task, the data were analyzed using a 3 x 2 (Group X Test) ANOVA with repeated measures on the last factor (p<.05). The results indicated significantly faster performance for the older children (third and fourth grades) than the younger children for all three tasks. For the two-handed penny task, the control groups performed the task significantly faster than the experimental groups. The experimental groups performed significantly faster on the posttest than the control group on the pegboard task. Therefore, the only task that was statistically influenced by the cup stacking unit was the pegboard task. Overall, the results of this study indicate that participation in a three-week instructional unit does not significantly improve hand-eye coordination in elementary age children. More research is needed to determine the influence of long-term participation on the hand-eye coordination of children.Keyword(s): assessment, elementary education, research