The research was conducted on 211 strains of Staphylococcus isolated in the three-year period 1972-1974- The coagulase, the hemolytic quality, mannite fermentation, pigment and penicillinase production were studied. The 211 strains of Staphylococcus were divided into 2 groups according to their origin: the 1st group included germs isolated from material which was certainly pathological, the 2nd group included strains isolated from various sources (throat, nasal, rectal, swabs, urine). The results, summarized in the Tables, led to the conclusion that even if the coagulase is the most significant characteristic in establishing pathogenicity of the Staphylococcus, the production of pigment and penicillinase also prove to be valid parameters of pathogenicity.