Female NMRI-mice were injected intraperitoneally and subcutaneously with zinc chloride and lead chloride as well as with a mixture of both. The mice were also immunized with foreign-proteins. To demonstrate the interconections, the heavy metals and the proteins were injected separately, as was the heavy-metal-protein-suspension. The results of the studies are as follows: 1. Intraperitoneal application of lead leads to a significant elevation of the antibody titer, using bovine immunglobuline while zinc applications showed no rise or slightly raised antibody formation. 2. It could be demonstrated that the admixtion of zinc chloride depresses the stimulatory effect of lead chloride on the immunization. 3. With the heavy metal-protein-mixture is proved that lead chloride stimulates the antibody production more than zinc chloride. To explain these results, it is discussed whether the adjuvant effect of lead is inhibited by zinc whereas zinc itself stimulates the immunsystem through another working mechanism.