To prevent the spread of SARS-CoV-2 infection on March 16, 2020, Government of Kazakhstan has announced a nationwide emergency and imposed unprecedented lockdown restriction measures. The objective of this study is to evaluate the changes in air quality during the lockdown period in the four cities of Kazakhstan: Aktau, Atyrau, Karagandy, and Shymkent. The data on concentrations of Total Suspended Particles (TSP), NO2, SO2, and CO were collected for 56 days during the lockdown (16 March – 11 May 2020), during 56 days before lockdown (20 January – 15 March), and the same periods of the previous years (2018 – 2019). During the lockdown period (spring 2020), concentrations of TSP, NO2, SO2, and CO (on average for 4 cities) declined by 19, 8, 17, and 25% respectively, compared to the same period in 2018 – 2019, with significant variations between cities. In the pre-lockdown period (winter 2020), concentrations of TSP, NO2, SO2, and CO (on average for 4 cities) also declined, by 16, 13, 7, and 9%, respectively, compared to the same period in 2018 – 2019. Thus, reductions in the concentration of pollutants during 16 March – 11 May 2020, compared to the same period in the previous years could be only partially attributed to lockdown restriction measures and may be also affected by annual changes. In addition, despite some improvement in air quality during the lockdown period, in three out of four cities, the levels of air quality were still high and not safe.