Acute disruption of the corneum barrier with adhesive tape resulted in enhanced permeability and alterations in the skin immune system in such a way that epidermal Langerhans cells (LCs) functioned as vigorous antigen presenters for cytotoxic T lymphocytes (CTLs). In both human and murine systems, topical application of tumor-associated antigen (TAA) peptides onto stratum corneum barrier-disrupted skin specifically induced tumoricidal immune responses in vivo and in vitro. In addition, for reasons of simplicity, safety and effectiveness, percutaneous peptide application has demonstrated a certain degree of feasibility in clinical approach in patients with melanomas. In the future, resolution of some of the outstanding issues regarding the selection of the most effective adjuvants in combination with barrier disruption, development of the effective methods of T helper (Th) 1 cell-mediated CTL induction, and depletion of regulatory T (Treg) cell-mediated immune suppression from tumor bearers would appear as essential for improvement of percutaneous TAA peptide immunization.