The present study aims to fill the gap by comparing mega sport sponsorships to local sport sponsorships relative to consumers’ perceptions. Specifically, the study examines whether or not event size has significant impact on consumers’ perceptions of goodwill. In the relationship between event size and perceived goodwill, sponsorship duration and sponsor-event congruence are tested as moderating variables. Finally, it is anticipated that perceived goodwill affects attitudes toward the sponsor, subsequently influencing purchase intentions. To support the hypotheses, the current study conducted an experiment with a 2 × 2 × 2 between-subjects factorial design: (1) event size, (2) sponsorship duration, and (3) congruence between a sponsoring brand and a sponsored event. Through a three-way full-factorial ANCOVA (analysis of covariance), the current study showed the main effects of event size, and the moderating effects of sponsorship duration and sponsor-event congruence in the relationship between event size and perceived goodwill. In addition, regression analyses tested the relationships among the dependent variables including perceived goodwill, attitudes toward the sponsor, and purchase intentions. The research results entail that a corporate sponsor generates greater perceptions of goodwill when it sponsors a local sport event than when it sponsors a mega sport event (H1). The research findings additionally identified the moderating roles of sponsorship duration (H2) and sponsor-event congruence (H3) in the relationship between event size and perceived goodwill. Further regression analyses showed the paths from perceived goodwill to attitude toward the sponsor (H4) and from attitude toward the sponsor to purchase intention (H5) were significant. According to the mediation test, the indirect-only mediation of attitude toward the sponsor between perceived goodwill and purchase intention was confirmed. The results of the present study may contribute to the sport sponsorship literature both theoretically and practically. The study is grounded in balance theory, attribution theory, and meaning transfer theory, and the results should further extend our knowledge in these areas. Further, practitioners may discover the merits of a corporation sponsoring local sport events at lower costs, and the importance of duration and congruency. The findings of the current study may provide future research directions in the sport sponsorship area.