
The provision of good indoor air quality (IAQ) in schools is essential for students' health as well as for their academic achievement. The purpose of the present study was to assess the ventilation rates in a representative sample of (N= 36) primary schools in Eastern Province by using CO2 as an indicator of ventilation. The results revealed that only four schools (10%) of the total primary schools selected in this study have adequate ventilation. The average mean CO2 rates were 1333.9± 475.4 ppm and 1198.5± 303.6 ppm at 9:00 AM in rented and governmental schools building, respectively. On the other hand, at 12:00 PM the mean CO2 rates were 1780.4± 636.5 ppm and 1563.3± 595.7 ppm in rented and governmental schools buildings, respectively. Interestingly, the average mean of CO2 rates in rented schools were significantly higher at 9:00 AM and 12:00 PM (p= 0.020) and (p= 0.028), respectively. In conclusion, the ventilation rate is relatively poor since mean CO2 rates in schools exceeded the recommended guideline (1000 ppm) in the majority of schools. Raising awareness of schools and communities regarding the importance of ensuring good ventilation in classroom is highly required. Policy makers should work hard in parallel with community to ensure better healthy and safe schools environment. Emphasis should be given to the research conducted in different schools regarding broader aspects of school environment and their potential hazards.