From studies on high-and-low molecular-weight candidial toxins, with special reference to the etiopathology of experimental-weight candidial toxins, with special reference to the etiopathology of experimental C. albicans infection, it may be concluded that these toxins, particularly the high-molecular-weight ones, play a very important role as parasitic factors in the extablishment of the infection, possibly also affecting its course. This concept of the role of Candidial toxins may be considered also applicable to the establishment of natural candidosis. It is speculated that these toxins might be more or less ubiquitously produced in pathogenic fungi, not only C. albicans but also other species of the genus Candida as well as those of other fungal genera. They may be to some extent related to the etiopathology of their respective fungal infections.