To determine a possible role of Langerhans cells in viral infection of skin, we studied the distribution of Langerhans and indeterminate cells in the lesional skin of mollusca contagiosa, verrucae vulgaris, plantar warts, and condylomata acuminata. A total absence of Langerhans and indeterminate cells was observed in molluscum contagiosum, but their number appeared to be normal or increased in the perilesional normal skin. Few Langerhans and indeterminate cells were seen in the suprabasal location in verrucae vulgaris and plantar warts, and normal numbers were noted in the perilesional skin. In contrast, a larger number of Langerhans and indeterminate cells reaching up to stratum granulosum were found in the condylomata acuminata. It is possible that alteration of keratinocytes by viral infection may effect the migration of Langerhans cells to the epidermis. The lack of Langerhans cells may lead to a paucity of inflammatory response (in particular, T cell-mediated response) to the cells infected with the virus.