In studies for the chronic toxicity of estrogens and gestagens, lysozyme and hemolytic complement (CH50U) in sera of beagle dogs and minipigs were measured. Various doses of the sexsteroids were given: 0.01 mg, 0.1 mg and 1.0 mg/kg respectively. The influence of the steroids on the tested parameters after an application for 6 months was not significant, only in a single series with unphysiologically, high dosages of the preparations were some values changed significantly.