Pemphigus is a relatively rare autoimmune bullous disorder involving the skin and mucous epithelia. Clinically characterized by blisters and erosions, its histological hallmark is acantholysis induced by IgG antibodies (ab) against desmoglein 3 and/or desmoglein 1. The role of ab alone in inducing acantholysis is still a matter of debate as several mechanisms could be involved. Another intriguing area of research is the trigger factor inducing autoimmunity in pemphigus patients and the role of T and B cells in this process. This paper will review the data related to the mechanisms of acantholysis between keratinocytes and the role of T cell in this phenomenon.