This paper presents the Post Occupancy Evaluation of the first naturally ventilated lecture theatre built in a tropical region. The challenge was to design a bioclimatic amphitheatre of 550 seats, which does not use air conditioning and remains comfortable at the same time. A post-occupancy evaluation has been carried out based on, in parallel, indoor and outdoor measurements, and a user's survey. Airflow measurement is used to check the good performance in terms of natural ventilation. A follow-up of the building's actual consumption has been carried out as well, which showed overall positive results. 92% of the users feel comfortable or slightly comfortable during the hottest days. Nevertheless, 50% of them would prefer to get more air movements. In terms of energy consumption, the lecture theatre consumes four times less than a standard one.