The theory of planned behavior is a well-established theory in predicting human behavior. However, there is evidence of an inconsistent relationship between intention and behavior. Therefore, the purpose of the current study is to further investigate the gap between intention and behavior. The study proposes intention stability as the moderator. Participants (N = 154, M age = 23 yr., SD = 6.7) were recruited from Internet volleyball forums and local volleyball courts in Taiwan. Multiple hierarchical regression was used to analyze the data. The results indicated that perceived behavioral control significantly predicted game-attending behavior through intention. However, attitude and subjective norms did not significantly predict behavioral intention. In addition, intention stability moderated the relationship between intention and behavior and indicated the relationship between intention and behavior was strong when intention stability was high. On the contrary, when intention stability was low, the relationship between intention and behavior was weak. Implications and applications are discussed.