Purpose of the article: Presentation of the issue of brand sponsorship of events in the light of the use of social media for the purposes of brand management in the customer-based brand equity paradigm. Methodology/methods: Two brands (CocaCola and Carlsberg) which were the official sponsors of a sports event (EURO 2016) were monitored in social media. For this purpose information gathered by socialmention.com and likemore.pl were used. Presentation of the results of the analysis required the use of descriptive statistics as well as the Wilcoxon test and a network graph. Scientific aim: Determination of the scope and nature of the influence of sponsorship of an international sports event on the way a brand is perceived by social media users based on a selected set of data derived from brand monitoring. Findings: In case of Carlsberg the attitude of social media users did not change during EURO 2016, however, majority of their statements was connected with the issues related to this sports event. In case of Coca Cola, the perception of the brand by its clients changed within the studied period of time, however, the issues related to EURO 2016 were only one of many other issues raised by them. Conclusions: Assessment of the influence of brand sponsorship of an event on social media users' perception faces the following difficulties: scope of monitoring, its efficiency, choice of data set generated by the monitoring tool for the analysis, level of recognition of brands and brand multi-sponsorship (parallel engagement of the brand in many events).