Two studies examined the reliability and validity of the Physical Activity Enjoyment Scale (PACES). In Study 1, each subject rode an exercise bicycle under control and external focus conditions. The PACES had high internal consistency in both conditions. As predicted, subjects reported enjoying the exercise more, as measured by the PACES, in the external focus condition. Moreover, there was a significant negative correlation in the control condition between subjects' PACES scores and their scores on a measure of boredom proneness. In Study 2, each subject rode an exercise bicycle and jogged on a minitrampoline in separate sessions; each then chose one of these activities for their third session. Again, the PACES had high internal consistency. And, as predicted, there was a significant relationship between subjects' PACES ratings (completed after each activity) and their choices of activity. Test-retest reliability was high for jogging and moderate for bicycling. These studies provide preliminary evidence of the reliability and validity of the PACES.