The data of pathogenicity factors of mollicutes and mechanisms of the effect of these microorganisms on the organisms they have infected and, first of all, on people occur in countless literary sources. Such data have been accumulated for above 100 year of mycoplasmology existence as science and remain unachievable for most interested specialists. An attempt has been made to generalize in maximum complete volume everything known about pathogenic potential of human and other mollicutes, their pathogenicity factors and mechanisms of their realization on the dramatic changes occurring in the affected organism under the effect of mycoplasmic infection.