Researches on the content of Zn, Pb, Cu, and Cd in some medicinal plants have been carried out on the area of Medicinal Plants Garden of the Medicinal Academy in Wrocław, situated along a busy traffic road in the years 1990-1992. Four species have been tested on the lavel of contamination caused by exhaust gases at varied distances from the traffic road. The species were: Sambucus nigra L., Digitalis purpurea L., Taraxacum officinalis L. and Matricaria chamomilla L. Flowers and leaves were submitted to examination and an absorption spectrophotometry (AAS-1) was used to determine the level of contamination. The greatest amounts of heavy metals have been found in plants growing closest to the traffic road and the number of cumulated elements depended of the species and the anatomical parts thereof. The most contaminated by Cu, Zn, Pb and Cd were the plants of Digitalis purpurea L. The flowers of Sambucus nigra L. contained markedly more heavy metals than their fruits. The level of Cu and Cd was in the majority of plants tested within the natural background whereas the amount of Zn and Pb were considerably higher, thus eliminating the harvesting of medicinal herbs along traffic roads.