This study examined the effects of mental practice (MP), slow motion mental practice (SMMP), and attention placebo control (APC) on the performance of the putting throw in Frisbee disc golf. Subjects were randomly assigned to the three groups and participated in a pre-treatment performance session, a five session treatment phase, and a post-treatment performance session. Performance changes were examined, as were repeated measures manipulation check questionnaires. It was hypothesized that the SMMP group would demonstrate the greatest improvement due to the possible imagery-enhancement effects of the slowed presentation of mental practice, that the MP group would also show significant improvement, and that the APC group would show slight non-significant improvement because of expectancy factors. Performance analysis of variance (ANOVA) revealed no significant main or interaction effects, but did indicate a slight trend toward improvement on the repeated measures factor. A number of suggestions for the improvement of the present design were offered, and it was concluded that further, methodologically-sound and theoretically-based experimentation is needed in this area. (Authors)