This study assessed the role of behavior enjoyableness in development of long-term behavior. First, as expected from the literature on attitude and behavior change (Ajzen, 1991; Ryan & Deci, 2000), initial enjoyableness of a behavior predicted how successful participants were in performing the behavior in the short term (i.e., the time until they first violated their behavioral intentions). Of primary interest, repeated successful performance was, in turn, associated with an increase in reported enjoyableness of the behavior in the longer term. The study demonstrates the importance of a reciprocal relationship of behavior enjoyableness and performance for behavior change, such that even initially non-enjoyable behaviors can become more enjoyable with repeated performance. These findings are particularly relevant for long-term, goal-related behaviors.