Specific immune reactions in man subsequent to infection by wart virus have been the subject of various studies. Most concern humoral immunity and show an antibody distribution which rises with age comparable to the viral exanthems of childhood with a maximum at 20 years and show decline thereafter. The acquisition of antibody is prolonged and sometimes irregular and its role in wart healing is questionable. The most recent work on cellular immunity has demonstrated profound abnormalities in cases of profuse verrucosis and in epidermodysplasia verruciformis, increased incidence of warts in immunodeficient states and the existence of specific reactions to viral antigen both in vitro and in vivo. Such results indicate and predominant role for cellular immunity in the evolution of this viral infection and suggest the possibility of specific immunotherapy. Very recent studies of biochemical identification of purified virus particles of various clinical types of wart show viral heterogeneity. This fact implies the need to reexamine these immune reactions in the light of the existence of crossed serological reactivity and specific wart treatment.