Total T and T gamma cell populations were studied in patients suffering from mammary of cervical uterine cancer. The results show that for both groups of patients there were no changes in the total T cell counts when compared with controls: but T gamma subpopulation values were greatly increased in the cancer patient groups, irrespective of in the mammary cancer group, whether the tumor mass was present at the moment of evaluation or surgically removed. The percentage of T mu cells returned to normal level after local irradiation treatment in all cases studied. We speculate about the possible changes in lymphocyte migration as a consequence of irradiation which may affect cells in the blood stream.