The paper presents monitoring results and environmental pollution assessment for Gdansk-Sopot-Gdynia Tricity (Poland). Precipitation samples were collected at ten sites in monthly cycles over a period of 4 years from January 1, 1998 to December 31, 2001. The following analytes were determined in the samples: NO3-, SO42-, F-, Cl-, PO43-, NH4+, Ca2+, K+, Mg2+, Na+. These results were subjected to full statistical evaluation and chemometrical analysis (time series, analysis of variance and principal component analysis). The obtained results allowed us to determine the relations between variance of average concentration levels of analytes in rainfall samples, depending on the season and the amount of rainfall. Chemometrical analysis confirmed that the composition of inorganic pollution present in the precipitation samples taken within the Tricity was-to a large degree-affected by the location of the area and proximity of the Baltic Sea. A characteristic feature of the region is the presence of industrial plants producing granulated phosphatic fertilizers, which contributes to the average level of PO43- and F- ion concentration in rainwater. (C) 2002 Elsevier Science Ltd. All rights reserved.