Air pollution with SO(2), NO(2), particulate matter PM10 and O(3) in Poland was described with an air quality index (AQI) both in the whole country and in particular regions. A decrease in values of sub-indices for all studied pollutants (esp. of SO(2)) averaged over the country in 1997-2009 years was obsd. The average AQI decreased also and was lower than 1 since 1998 (about 0.6 in 2007-2009). The highest AQI was found for the Silesian region (0.8-1.0 in 2007-2009).