The aim of our study was to demonstrate a possible correlation between some biochemical and biological markers of the degree of virulence of the investigated strains of Acanthamoeba sp. The results obtained demonstrated a significant correlation between the activity of proteases, peroxidases, and superoxide dismutase and the degree of virulence of the strains as previously defined by tests on mice. The results also proved that the strains that killed some of the infected mice were characterized by the highest value recorded for the activity of peroxidase and the lowest value obtained for the activity of superoxide dismutase.