Despite the growing role of sports sponsorship as a promotional tool in the marketing activities of firms worldwide (Pruitt, Cornwell, and Clark, 2004; Close et al., 2006; Lacey, Close, and Finney, 2010; Sneath, Finney and Close, 2005; Madrigal, 2000), academic research in this area has been limited (Speed and Thompson, 2000; King, Kahle and Close, 2011). This paper focuses on the study of consumer behavior in the area of sports and sports sponsorship. Specifically, this research examines the effects of congruencies among professional baseball team’s personality, sponsor brand’s personality, and fan’s self-concepts on the evaluation of teams and sponsoring brands. We also unveil the underlying mediating and moderating mechanism of the effects. More specifically, hypothesis 1 was set to find the moderating role of attachment style on the effect of actual self-concept congruency between fans and teams on team identification and attendance intention for the sports event. We show ‘team identification’ mediates the effect of self-concept congruency moderated by avoidance and anxiety attachment on sports event attendance intention (hypothesis 2). Hypothesis 3 examines the moderating effect of anxiety attachment on the effect of team and brand personality fit on the attendance intention when they are congruent on the dimension of sincere personality, whereas hypothesis 4 investigates if avoidance attachment moderates the effect of team and brand personality fit on the purchase intention when they are congruent on the dimension of exciting personality. A 2 (self-concept congruency: high vs. low) × 2 (anxiety related attachment: high vs. low) × 2 (avoidance related attachment: high vs. low) ANOVA yielded a significant three-way interaction effect on team identification (F=3.675, p=.057) and on attendance intention (F=4.500, p=.035). Subsequent two way ANOVAs revealed significant moderating effects of anxiety attachment when avoidance attachment was high (on team identification: F=3.827, p=.053; on attendance intention: F=5.697, p=.019), but insignificant moderating effects of anxiety attachment when avoidance attachment was low (on team identification: F=2.369, p=.126; on attendance intention: F=.653, p=.421). Under the condition of high self-concept congruency, the effect of avoidance attachment on team identification and attendance intention was greater for less anxiously attached participants. On the other hand, the effect of avoidance attachment on team identification and attendance intention was weaker for more anxiously attached participants. Under the condition of low self-concept congruency, however, no significant interaction effect was found. Since less avoidant individuals tended to shun social interactions less, high self-concept congruency led to higher team identification and enhanced attendance intention when the participants’ anxiety attachment were high than low. A series of regression analyses for mediation test showed that the originally significant self-concept congruency × avoidance × anxiety attachment three-way interaction (β=.274, p=.000) became insignificant (β=-.016, p=.580) on sports event attendance intention after the potential mediator, team identification (β=.511, p=.000) was included in the model. The Sobel test (t=4.686, p=.000) and Preacher and Hayes (2004)’s bootstrap procedure (95% CI =[.2267 to .8050]) also confirmed a significant indirect effect of team identification. A regression yielded a significant interaction effect of ‘perceived team-brand personality fit’ × anxiety attachment (β =-.428, p=.009) confirming that anxiety attachment moderated the effect of ‘perceived team-brand personality fit’ on attendance intention when team’s and the sponsoring brand’s personality were congruent on the sincere dimension of brand personality. On the other hand, avoidance attachment style moderated the effect of ‘perceived team-brand personality fit’ on purchase intention when team’s and the sponsoring brand’s personality were congruent on the dimension of exciting brand personality (β =-.295, p=.080).