Sport sponsorship has increased the value of sponsoring firms by becoming a key factor in the communication mix with customers and investors that can enhance corporate image and stimulate the sales of products and services (Javalgi, Traylor, Gross, & Lampman, 1994). Several studies show that sport sponsorship can lead to positive stock returns, which is consistent with modern corporate finance’s ultimate goal of maximizing firm value (Chen & Chen, 2012; Cornwell, Pruitt, & Clark, 2005; Miyazaki & Morgan, 2001; Pruitt, Cornwell, & Clark, 2004; Reiser, Breuer, & Wicker, 2012). In line with such findings, spending on sport sponsorships has also increased globally over the last several decades in conjunction with the thriving sport industry, as indicated by the popularity of major sporting events such as the World Series and Super Bowl.1 It is also worth noting that compared to sport sponsorship announcements, team performance has a more direct impact on the value of corporate sponsors (Ashton, Gerrard, & Hudson, 2003; Chen & Chen, 2012; Dobson & Goddard, 2011). To the best of our knowledge, however, none of the empirical studies has attempted to investigate whether the team performance is spilled over to affiliated firms of sponsoring firm (i.e., subsidiaries), and furthermore, what causes the heterogeneity in the impacts of team performance on affiliates of sponsoring firms’ value. In this study, we therefore attempt to answer these questions by utilizing several unique features of the South Korean professional baseball league, known as the Korean Baseball Organization (KBO).