Objectives: This study aimed to examine the change in the air quality parameters of 31 cities that were af- fected by the strict measures taken in Turkey during the months of March, April, and May and their relationship with the activity parameters. Methods: Thirty-one cities included in this study were assessed in terms of their average particulate matter (PM10 ), sulfur dioxide (SO2 ), carbon monoxide (CO), nitrogen dioxide (NO2 ), and ozone (O3 ) values in the months of March, April, and May between 2017 and 2020 and their activity data in the same months of 2020, which had six different subdimensions. Results: When the compared the 3-month average air parameters of the cities and the 3-month average param- eters of the previous 3 years, the PM10 and NO 2 levels decreased from 47.6 μg/m 3 to 38.1 μg/m 3 and from 54.8 μg/m3 to 25.7 μg/m 3 , respectively (p=0.001 and p=0.001). When the change in the air quality parameter and the activity change correlation were evaluated, a statistically significant correlation regarding “retail and recreation,” “workplaces,” and “residential,” which were the three subdimensions of the SO 2 change activity was determined (p=0.034, p=0.002, and p=0.003, respectively). In the linear regression models established, it was determined that “workplaces” had a statistically significant relationship regarding SO2 change (r=0.339, p=0.038). Conclusion: The decrease in air pollution that is an indirect positive effect of the pandemic on the environ- ment is temporary, but governments should learn from this lockdown on how to reduce pollution on a long- term basis.