The Niepołomice Forest, a large forest complex typical of Central European lowlands, is located near an urban-industrial agglomeration in southern Poland. During the past 20 years, SO2 emissions from industry decreased from 75,000 t yr-1 to 6000 t yr-1. Concentration of SO2 in the air, and pH, SO4 -2 concentration in bulk precipitation were measured during the last 11 years and compared with data from the 1970s. The spatial distribution of concentrations and deposition of S were calculated on the basis of 30 bulk precipitation samples in 1999-2000. Mean annual concentration of SO2 in the air was 8.25 µg m-3 in 2000, that is 2.5 times lower than during the period 1967-1978. At the beginning of the 1990s the concentration of SO2 exceeded the critical level for plants during 3% of the days over the year, and at the end of the 1990s only on single days. In 1999 and 2000 the yearly mean concentration of S-SO4 -2 in bulk precipitation in the Niepołomice Forest was 1.11 mg l-1, ranging between 0.99 and 1.27 mg l-1 in the forest complex. The yearly mean sulphur deposition (S-SO4 -2) was 8.1 kg ha-1, varying from 7.3 to 8.9 kg ha-1. The present concentrations and deposition of S-SO4 were a quarter those of 1974-1978. The spatial distribution of S deposition pointed to the influx of S compounds to the Niepołomice Forest with air masses from the west. The yearly mean pH of atmospheric precipitation was 4.64 (1999-2000), and was steady within the forest complex. In the Niepołomice Forest, atmospheric precipitation was more acid recently than in the 1970s.