Nowadays, cities are increasingly promoting active transportation modes and public transport to reduce car use. In parallel, the management of problematic ambient factors such as the odour in public transport systems is becoming a very important issue due to crowding that is constantly increasing. In this context, in order to contribute to public policies and to reduce olfactory nuisances, we evaluated the effects of ambient scent diffusers on the user experience and their attitude toward the use of such devices in public transport. We collected data among users of the tramway of Montpellier (France). They were questioned on-board about the ambient odour in two different situations. Users answered either in presence (70 users) or absence (97 users) of an ambient scent in the tramway carriage they were in. Our main results show that the presence of an ambient scent increased the pleasantness rating of the ambient odour and attenuated the perception of other odours inherent to public transport (perspiration, food, perfumes, etc.). Furthermore, the user attitude toward the presence of such a device in tramway carriages improved when the ambient scent was present. Thus, ambient scents might be a great tool in order to improve the olfactory comfort in public transport.