Modern urban lifestyles have most likely generated a loss of awareness of the bio-cultural benefits derived from the presence of trees and forests in cities. The present study aimed at understanding the level of awareness and the ability to express significant relationships, both positive and negative, on ecosystem services and disservices by the citizens of a Mediterranean city where thermal comfort during the summer period can be particularly problematic. A questionnaire consisting of multiple-choice and open-ended questions was disseminated to citizens of Florence, Italy. The open questions allowed respondents space to describe what they perceive are the benefits and disbenefits of urban trees. Meanwhile, geospatial and climate data were processed in order to check the vegetation and microclimate conditions of the city areas where the 592 respondents live. The vast majority of respondents felt Florence is unbearably hot in summer with 93% agreeing the city needs more trees, and shaded places were perceived as the most important feature of urban green space. The results reveal many positive and negative associations to different species of trees and bring out a rich mosaic of perceptions towards urban green spaces and the features they contain. People are generally aware of a wide range of the benefits trees provide to communities and a good knowledge of the microclimate modification properties was revealed. Many of the popular public tree genera in the city, such as Tilia, Platanus and Pinus were favored by residents however there was some overlap with trees that provoke negative experiences, and this information can be useful to city planners aiming to maximize ecosystem services and minimize ecosystem disservices.