Sustainable practices aiming to reduce environmental impacts have become key guiding principles of events, but initiatives focusing on the economic impacts and on supporting the local economy and society are also gaining more emphasis in event planning and management. Music festivals attracting larger audiences are becoming especially aware of the importance of sustainability as well as of their role in the process of raising participants’ awareness of it. The paper aims to assess the initiatives of the Street Music Festival in Veszprém, Hungary, one of the flagship events of the city, from both the participants’ and the organisers’ perspective. For the investigation of participant attitudes, a questionnaire survey was conducted, while the organisers’ views on sustainability were sought through interviews. The findings show that although respondents rate the importance of sustainability as very high, their contribution to responsible consumption is far from what could be considered sustainable, therefore better communication of the initiatives or stricter rules need to be introduced. The interviewees revealed that organisers consider economic sustainability just as important as the environmental issues, and gave an insight into the rationale behind sustainability enhancing initiatives, some of which have a marketing function as well as protecting the environment.