This review deals with autoantibodies, autoantigens, immunopathogenetic mechanisms and their consequences in autoimmune diseases caused by cytotoxic antibodies. Findings demonstrating the pathogenicity and pathogenic potency of antibodies, the involvement of complement and polymorphonuclears, and the chain of events leading from the start of immune reactions to clinical signs and symptoms are stressed. It is shown that the immunopathogenesis of this group of diseases can be deduced from only a few related immune mechanisms while the heterogeneity of clinical syndromes can be explained primarily by the function and localization of autoantigens. Questions still open and findings not yet understood are pointed out. From the progress of immunology in recent years further diseases can be expected to be recognized as type II autoimmune diseases in the years ahead notably by the combined application of immunological and physiological or pharmacological methods.