Despite the available information on variations in the erythrocyte chain of homeostasis under the conditions of drug-induced toxic damage, the question of the biochemical characteristics of erythrocytes in the expose of toxic doses of paracetamol on the background of dietary imbalance in protein remains open. 96 white nonlinear rats were used for the study. During the experiment, the animals consumed a semi-synthetic diet AIN-93 in accordance with the recommendations of the American Institute of Nutrition on the principle of paired nutrition, taking into account the amount of dietary protein per kilogram of diet. Modelling of acute toxic lesions was performed by administration to experimental animals of acetaminophen per os at a rate of 1250 mg/kg body weight. We found that toxic damage by acetaminophen is a key factor in reducing the level of total hemoglobin in the blood of animals (40% compared to control) with a simultaneous decrease in its average concentration (18%) and content in a single erythrocyte (35%), indicating the development of hypochromia, which is an indicator of iron deficiency in the body (iron deficiency anaemia). The synergistic effect of nutritional protein deficiency and the exposition of toxic doses of acetaminophen is accompanied by a decrease in total erythrocytes (50% compared to control) due to their increased hemolysis (up to 32% in 0.9% NaCl) with a simultaneous decrease in hematocrit up to 16% and the average volume of erythrocytes (1.4 times compared with the control). At the same time, the established changes in oxyhemoglobin decrease against the background of increased fetal hemoglobin content under the conditions of toxic damage and alimentary protein deficiency may serve as an additional criterion for comprehensive assessment in the diagnosis of anaemic syndrome in inflammatory diseases of different genesis against nutrient-associated conditions. Thus, the study of changes in erythrocyte indices in the development of acetaminophen-induced lesions on the background of nutrients’ alimentary deprivation can increase the effectiveness of monitoring the course of these pathologies and approaches to their correction.