Abstract Gaseous pollutants negatively affect air quality and consequently human health and wellbeing. Thus, the University of Patras Campus (UPC) air quality is evaluated in comparison to Patras downtown air quality, regarding nitrogen oxides (NO x ) and carbon monoxide (CO) concentration levels. The air pollution station installed at the suburban area of UPC was monitoring the air quality during the period 2014–2018. The daily average concentrations ± standard deviations recorded by continuous measurements of NO, NO 2 , NO x , and CO were 0.4 ± 0.5, 4.6 ± 2.7, and 5.0 ± 3.0, and 39.3 ± 64.1 μg m −3 , correspondingly. These values are lower than the corresponding ones measured by downtown monitoring stations during 2001–2018. After analyzing the data recorded, the diurnal, weakly and yearly variations of NO, NO 2 , NO x , CO concentrations and NO/NO x , NO 2 /NO x , NO/NO 2 ratios were obtained. The yearly variations show that the pollutant concentrations at UPC are below the legislation limits. On the contrary, in Patras Downtown only NO x concentrations overcome the limit, while NO 2 concentrations found marginally below the limit during the last decade. Statistical analysis showed that concentration levels are affected by seasonality and meteorological parameters. The present findings may be useful in environmental impact assessments necessary for sustainable development projects.