This article is devoted to the personnel of the 3rd Special Infantry Brigade, a unit that was part of the Russian Expeditionary Corps in France. Despite the presence of works dealing with general issues of the formation and combat path of Russian troops in France, the personnel composition of the units has not been fully studied. Examining cases presented in central archives, the authors analyze over eight thousand records, which allows them to get an idea of the personnel characteristics of a specified military unit. Based on socio-demographic and professional characteristics, they compile a generalized portrait of soldiers and officers of the 3rd Special Infantry Brigade. The personnel information presented in the work is grouped into tables and concerns the ranks called up from the territory of Perm Province, whose share was 25 % of the total number of the brigade. The authors conclude that officers who had combat experience were assigned to regiments, and those who did not take part in the battles received positions in the marching battalion. Most lower ranks belonged to the peasant class and had restrictions for military service for health reasons. Data on combat experience, education, and categories of conscription of military personnel make it possible for the authors to make assumptions about the combat effectiveness of the 3rd Special Infantry Brigade. Finally, the authors make conclusions about the features of the personnel, which are compared with the all-Russian trends of 1916–1917. At the same time, special attention is paid to the fact that the collective portrait of the personnel is typical of military units formed during the final period of the First World War.