Nowadays pollution of the environment is one of the major problems of mankind. Moreover, studying of the effect of different kinds of medicine on selected, specially bred, non-exposed to external pollutants animals is becoming distant from reality. Thus in this work we have investigated the modifying action of heavy metals on anti-inflammatory effect of aspirin. The investigation were carried out on rats which were injected during 7 days intraperitoneally by PbCl 3 , HgCl 2 , CdCl 2 in concentration of 100, 20, 1 mg/kg accordingly, modulating accumulation of the metals in the organism tissues. On the 8 days inflammation was invoked by formalin. As anti-inflammatory medicine was use aspirin. Judging by obtained results the conclusion can be drawn that cadmium in concentration 1 mg/kg significantly increases anti-inflammatory aspirin activity. The observed outcome can be explained in the following way. It is generally known that zinc in a certain concentration demonstrates anti-inflammatory properties. Being an element of the same group cadmium has similar properties and also can have anti-inflammatory action. Lead and mercury suppressed anti-inflammatory aspirin activity. Obvious inhibitory action of mercury and lead salts on aspirin action related to the fact that these elements by themselves were inflammation factors. From the obtained results the following conclusion can be drawn: a definite dose of anti-inflammatory medicine (aspirin) which is sufficient in normal conditions became less effective against the background of accumulation of ions of some heavy metals in an organism.