Patients with laryngeal cancer were examined immunologically before treatment and for 1–10 years after treatment. In the pretreatment group, the percentage of T cells, lymphocyte blastoid reaction (PHA, concanavalin A), and skin reactions (PHA) were generally in the normal range, but absolute numbers of T cells and lymphocytes were reduced in most patients. In the group with no recurrence after surgery, the absolute number of T cells and lymphocytes, IgG · FcR⁺T cells (T), and skin reactions was normal in many cases. The group with recurrence showed reduced percentage of T cells and an absolute number of T cells and lymphocytes. The absolute number of T cells and lymphocytes and the PPD skin reaction increased after surgery in some cases, but reductions in some of the parameters were noted in a few cases long after surgery. Radiation therapy for patients with tumors at early stages did not significantly change the percentage of T cells or the skin reactions.