The purpose of this study was to examine the effects of depleted self-control strength on skill-based sports task performance. Sixty-two participants completed the following: a baseline dart-tossing task (20 tosses), with measures of accuracy, reaction time, and myoelectrical activity of the arms taken throughout; a self-control depletion (experimental) or a nondepletion (control) manipulation; and a second round of dart tossing. As hypothesized, participants in the experimental condition had poorer mean accuracy at Round 2 than control condition participants, and a significant decline in accuracy from Round 1 to Round 2. Experimental condition participants also demonstrated poorer consistency in accuracy compared with control condition participants at Round 2 and a significant deterioration in consistency from Round 1 to Round 2. In addition, consistency in reaction time improved significantly for the control group but not for the experimental group. The results of this study provide evidence that ego depletion effects occur in the performance of a skill-based sports task.