The review presents problems of immunopathology of acantholytic pemphigus. Simultaneous increase of antibodies to desmoglein-1 and desmoglein-3 is revealed in pemphigus vulgaris and in pemphigus vegetans. In vulgar pemphigus with prevailing mucosal lesions the erosions appeared on the oral mucosa where desmoglein-3 was prevalent. The blister formation does not need complement activation as in other dermatoses, for the presence of framents of monoclonal antibody is sufficient. In pemphigus autoantibodies relate mainly to IgG4 subclass which does not activate complement, poorly activate effector cells through the Fc region and ineffectively crosslinks the antigen, which directly influences the desmosomal functions. In the case of atypical acantholytic pemphigus, non–desmoglein autoantigens may be revealed.