Erythrocytes, hemoglobin, hematocrit and morphometric parameters of erythrocytes can be an important tool for assessing the health, ecological and population status of mammals, but they have not been sufficiently studied yet due to the variety of living conditions of animals, difficulties in collecting and preserving samples.The aim of the study was to establish the parameters of erythrocytes of wild boars - one of the most significant game species in Russia, which also plays an important role in the spread of many dangerous diseases and parasites, including classical and African swine fever, tuberculosis, brucellosis, foot-and-mouth disease, Aujeszky's disease, echinococcosis, alveococcosis, trichinosis, etc. Blood samples were obtained from adult(n=25) and young(n=21) males obtained in the central part of the Kirov region.The studies were conducted on a MicroCC-20 Plus automatic analyzer. Stained smears were examined using a MEIJI TECHNO light microscope. The area of erythrocytes was measured using Vision Bio (Epi) software. The parameters of erythrocytes were established and statistically analyzed on the age of males are described for the first time. The features of erythrocyte indices depending on the age of males are described for the first time. Reliable differences (p<0.05) were determined between young and adult males in the number of erythrocytes (young 5.30±0.87·1012/l, adults 6.32±1.47·1012/l), their area (young 26.42±2.37 mkm2, adults 28.79±1.68 mkm2), hemoglobin concentration (young 115.00±22.28 g/l, adults 154.00±31.72 g/l) and hematocrit (young 32.10±7.20%, adults 42.95±12.02%). Using ANOVA-Test, a significant (p<0.05) influence of the age and body weight factors on the hematocrit level was established.Hematocrit is higher in adult males, who have a significantly larger body mass The reference intervals defined in this study provide a basis for interpreting hematological results in male wild boar of different ages when assessing veterinary risks and may help optimize resource management for this species.