The study of herbaceous vegetation growing in different parts of the City of Petrozavodsk varying in lead-pollution levels was conducted. It was established that the herbaceous communities formed at contaminated sites were characterized by fewer species (genera and families) than those in the relatively clean territories, a higher share of more tolerant species of the family Poaceae, and a decrease in the production of aboveground biomass. At the same time, a decrease in the absolute values of a majority of morphometric characters, among which the most sensitive to soil pollution is “leaf surface area” of the second leaf from the inflorescence, is observed in the dominant grass species (Dactylis glomerata L. and Phleum pratense L.). The conclusion on the applicability of a number of parameters characterizing the state of vegetation as a whole and individual plant species as criteria for assessing the level of environmental pollution with heavy metals (in particular lead) which, in turn, can be used for early diagnosis of diseases in the population inhabiting the territories, is drawn.