Background. To assess time trends in prevalence of pollen-related allergy in Saratov region during the last 3 decades . Materials and Methods. Agro-climatic, aerobiological monitoring (pollens of trees, grass, weeds were collected using gravimetric method and counts were done using a standardized protocol). Concentration of salts of heavy metals determined by means of mass - spectrometry in the pollen grains from plants, growing in city and village («dirty» and «clean» areas). Epidemiological (screening with questionnaire), clinical examination, skin tests were used to define the clinical diagnosis. Results. The pollen map of Saratov region has been changed because of climate, melioration and expansion of the Cyclachena xanthyfolia and other weeds. Detection of Pb, Zn,Cu,Ni in pollen grains collected from these plants in «dirty» areas showed that they accumulate heavy metals. The prevalence of pollinosis in 1977 in Saratov region was 1,4% , in 2002 -12,1%, in 2007-2,3%. Among all patients with pollen allergy 4,51% (1977), 5,2% (2002) and 16,0 % (2007) had positive skin tests with trees pollen allergens, 16,0, 36,7 and 29% -with grass pollen allergens and 78,5, 88,9 and 86,4 % -with weeds pollen allergens. Conclusion. Our results established increasing of pollinosis in Saratov region between 1977 and 2002, and there was a tendency towards stagnation in current symptoms of pollen-related allergy. High frequency of weeds allergens sensitization could be explained by allergenicity and prolonged blossoming period of new plants in this region.