Workers working in copper alloy factories (n = 40) who are professionally exposed to smoke and dust of copper, zinc, lead and cadmium and workers who are not exposed to toxic noxae (n = 15) were perorally administrated penicillamine for three days in order to evaluate deposits of these metals in their organisms. On the basis of the results obtained after penicillamine administration it was concluded that this substance can be useful in the evaluation of the presence of copper in workers. Penicillamine mobilisatory effect on lead and zinc in the organism was also proved. Because of competitive relations between copper and zinc (copper was a dominant noxa) it was not possible to evaluate the internal zinc presence. The mobilisatory effect of penicillamine on cadmium in the organism was not observed.