The lymphoid structures of inguinal lymph nodes and cells of the peripheral blood of 104 Vistar male rats of both experimental and control groups have been investigated by means of modern hystological and immunohystochemical methods. It has been revealed that the delta-sleep inducing peptide (DSIP) and Semax (synthetic analogue of ACTH 4-10) preliminary injection causes emotional stress influence on the increase of proliferative and destructive mac-rophage processes in the actively functional zones of inguinal lymph nodes. The relative quantity of small lymphocytes in the germinal centers of lymphoid nodules of inguinal lymph nodes has decreased in 1,3 per hour after the emotional stress in comparison with the indices of control groups. After the injection of DSIP the quantity of small lymphocytes resistant to stress in animals has decreased insignificantly, as for rats predisposed to stress it has increased in 1,2 in comparison with the data of control groups. It has been found out that the DSIP and Semax injection decreases stressinduced condition of lymphoid cells in peripheral blood as well as in lymphoid structures of inguinal lymph nodes