As a response to the increasing threat to sport events from climate change and expectations around climate change mitigation, sport event managers increasingly engage in environmentally-related initiatives that aim to reduce GHG emissions. One of the major contributors to GHG emissions at large sport events is spectators' travel and, thus, their associated modal choices. Building on the Sport Logistics Framework (SLF) and using the case study of Rapid Vienna, the largest football club in Austria, this study investigates spectators’ modal choice to systematically assess the total GHGs emitted by spectators at a professional football home game. Data was obtained from two sources: a) an extensive data set collected on Rapid Vienna season ticket holders, and b) three surveys at home games which, together, constituted 3317 valid responses. The calculation of the GHG emissions resulted in 99,548 kg GHG emissions per home game or 6.0 kg GHG emissions per spectator. It was also found that 42.4 per cent spectators arriving by car emit 71.6 per cent of GHG emissions, while in contrast, 52.8 per cent of spectators using public transport emit 27.1 per cent of GHG emissions. The results also indicate that the possession of an annual public transport ticket seems to determine travel behavior, i.e. the majority of spectators with an annual ticket are using it, while spectators without a ticket are using a car. As such, this paper not only provides an opportunity for academics and managers to benchmark the data in order to identify initiatives to reduce the impact of GHG emissions, but also allows for the systematic measuring of the environmental impact of fan and spectator travel.