the purpose of this study was to examine the effects of mental imagery in practice and in competition on the free throw shooting performance of basketball players. the subjects were 3 male university caliber basketball players. a single subject multiple baseline design was implemented. each subject was introduced to the imagery rehearsal intervention at different times during the 14 week competitive basketball season. free throw data was collected during 50 practice sessions and 32 games. results in both practice and competitive situations were examined using a graphed means comparison. in the practice condition an increase in free throw performance for all 3 subjects during the post treatment intervention was found. in the game condition, subjects a and b indicated post treatment improvement. mental imagery can be an effective strategy to improve free throw performance of some basketball players. further research in this area should involve controlled group examination using a larger sample size across a variety of tasks.