Among host lymphoid cells engaged in anti-tumor defence, tumor infiltrating cells (TIC) are apparently the most suitable for this purpose, due to feasibility of direct contact with tumor cells. The aim of the present study was to evaluate distribution of TIC which express phenotype of cytotoxic cells, in tissues of laryngeal carcinoma. Cryostat sections of surgical tumor samples were subjected to sensitive APAAP immunohistochemistry, following reaction with one of the panel of monoclonal antibodies (MoAbs) vs. several CD antigens and assessed semiquantitatively. It has been found that the content and distribution of potentially cytotoxic cells are quite heterogenous and vary from case to case in examined cancer. CD8+ cells and those bearing NK cell phenotype were the most frequently encountered, mainly within tumor mass. The cells belonging to NK cell subsets, detected by GL183 and EB6 MoAbs could be demonstrated in tumor proximity. TCR-1+ (tau/delta) T lymphocytes were quite a few in part cases. On the other hand, only a scarce number of cells among TIC expressed interleukin-2 receptor. It is concluded that in the vicinity of laryngeal cancer there are fairly large numbers of potentially cytotoxic cells, but at low or nil state of activation.