The paper presents a discussion on therapeutic results obtained with autotransfusion of laser-irridiated blood in 66 patients with stage II essential hypertension. Forty nine comparable patients entered a control group of conventional treatment. The test and control patients with stage II hypertension were examined for time course changes in T- and B-lymphocytes counts, the activity of the energetic enzymes (alpha-glycerophosphate dehydrogenase, succinic dehydrogenase, lactate dehydrogenase), serum immunoglobulins and circulating immune complex levels. It was established that the standart antihypertensive treatment foiled to restore normal parameters of immunity and to favor positive alterations in the activity of the enzymes in the blood lymphocytes, whereas auto-transfusion of laser-irradiated blood was found to stimulate immunity, especially cellular one. This occured in line with rise in the levels of lymphocytic dehydrogenases.