An analysis of short effect of pelvic irradiation on cellular and humoral immunity was made in 24 patients treated by irradiation alone or a combination of surgery and irradiation for uterine carcinoma, at 2, 6, 12 months after loco-regional therapy. Twelve months later there is a decrease of T lymphocytes (P = 0.01), whereas the B lymphocytes count is normal; the percentage of T and B lymphocytes remains stable, but the lymphocyte response to PHA after 3 days is reduced (p = 0.03). A significant decrease of immunoglobulins G, A and M is observed.