Objectives of the study are the experimental study of the adaptational changes occurring in the animal organism against the background of intoxication induced by low doses of benzene and acetone. Material and methods. There were studied 45 white mice divided into three groups: 1st group was consisted of intact animals; 2nd group included animals exposed to benzene through inhalation at a concentration of 32,6 mg/l; 3rd group included animals exposed to acetone at a concentration of 99,0 mg/l. Animals were poisoned five times in special chambers. Eosinophil, neutrophil and lymphocyte blood count (absolute) was determined according to common procedures. Results and discussion. After general anesthesia the benzene poisoning for the first time resulted in statistically significant reduction of the body temperature by 7,7oC, while after the 5th poisoning procedure this index was reduced slightly. Upon the first poisoning procedure in the animals after their emergence from anesthesia the leukocyte count was reduced by 26,3%, while eosinophil, neutrophil and lymphocyte counts were reduced by 41,3, 87,6 and 62,8% accordingly. The neutrophil to lymphocyte ratio (neutrophil/lymphocyte) was reduced by 39,49%. Before the fifth poisoning procedure, relative to baseline values, the reduction in lymphocyte count amounted to 13,3%; in eosinophil, neutrophil and lymphocyte counts - to 40,0, 1,7 and 13,7% accordingly, while the neutrophil/lymphocyte radio was reduced by 18,9%. After the emergence of the animals from anesthesia of the fifth poisoning procedure, the changes observed in the above-mentioned indices were much less than the changes caused by the first poisoning. Thus, reduction in lymphocyte count amounted to 13,8%; in eosinophil, neutrophil and lymphocyte counts - to 18,3, 4,8 and 17,7% accordingly, while the neutrophil/lymphocyte radio was increased by 16,9%. The results of chronical acetone poisoning of the animals show that after one month from the beginning of the study, the number of neutrophils and monocytes was reduced due to the slight reduction in the quantity of eosinophils, neutrophils and lymphocytes. Conclusion. The shifts in the leukocytic response due to еру repeated exposure to petroleum products through inhalation may be considered as the intensification of protective reaction.