Indoor Air Quality in educational environment is very important as it could interfere with the learning process. In this paper, the indoor air quality of selected lecture rooms of different sizes in an academic building was studied, involving measurements of indoor temperature, relative humidity, CO2 level and dust particles. A mixed result was observed on the relative humidity in the rooms. The levels of dust particles were observed acceptable although recorded higher in the small lecture room as compared to the lecture theater. The CO2 content in the lecture theatre was found to be higher than that in the small lecture room, and also exceeded the maximum recommended level. Overall, the results suggested that the lecture theatre needs attention in the aspect of Indoor Air Quality. © (2013) Trans Tech Publications, Switzerland.