Indoor Environmental Quality is of crucial importance to the health, well-being and productivity of its occupants, but it is often neglected and can have several negative impacts. This article presents the study carried out to assess the comfort conditions of two classrooms, located in building D on Campus 2 of the Polytechnic of Leiria, to understand the environmental conditions in which they are located. For this purpose, measurements were taken of some parameters that indicate indoor air quality, such as the concentration of carbon dioxide (CO2), particulates (PM2.5), bacteria and fungi. Measurements were also made of parameters related to thermal comfort, such as temperature and relative humidity. Finally, measurements related to lighting conditions were made, and illuminance levels were measured. The results obtained indicate that indoor air quality is sometimes inadequate, with a significant increase in the concentration of the parameters sampled (CO2, PM2.5, bacteria and fungi). They also indicate that in the case of thermal comfort, this is sometimes not achieved since the parameters sampled (temperature and relative humidity) are not in the range defined as ideal. In the case of lighting conditions, the results obtained show a negative scenario in general terms for both rooms in terms of illuminance levels, as they are lower or higher than the recommended levels. These results made it possible to identify the aspects in which proposals for improvement are needed and can be implemented in the near future.