The results of psychometric validation of a model of in-group identification (Leach et al., 2008) in three Russian samples are presented. The theoretical model is hierarchically structured. It includes five components (individual self-stereotyping, in-group homogeneity, in-group solidarity, satisfaction with in-group, and centrality of in-group identity) that form two second order factors (self-definition and self-investment). The samples included members of a social group (“students”, N=196), an ethnic group (“Russians”, N=146), and a religious group (“Orthodox Christians”, N=249). In study 1 different measurement models were compared for each sample using confirmatory factor analysis. The results support the hierarchical model with two second-order factors. The sets of items comprising each of the five in-group identification components have high internal consistency and discriminant validity. Study 2 focused on the validity of the new instrument in the ethnic group subsample using a number of Russian-language ethnic identity measures. The data indicate convergent validity of the new measure, indicating that its five scales tap into cognitive, affective, and behavioral components of identity with an ethnic group. The results of two studies show that the new Russian-language instrument based on the model of in-group identification has convergent and discriminant validity. Limitations of the study and future directions for the development of the instrument are discussed.