The present work fosters experimental measurements and mathematical modelling techniques to primarily determine the thermal and the relative humidity characteristics in the air-conditioned surgical operating room. The present work also demonstrates the effect of the various designs of surgical operating rooms and operational parameters on the flow pattern and temperatures characteristics. This study is a part of a more comprehensive investigation of the more important factors affecting the air environments in surgical operating room. Measured and predicted temperatures and relative humidity profiles are shown to be in good agreement. The present paper introduces several recommendations regarding the optimum design requirements of operating rooms to provide hygiene and comfort environment. Low humidity affects comfort and health. The present work offers examples of measured relative humidity profiles in an operating room in (New Kasr El-Aini Teaching Hospital – 1200 beds – Cairo University – Egypt). These experimental results were carried out to verify the proposed numerical procedure and particularly in the vicinity of the supply outlets and operating table.