This study aimed to evaluate whether cognitive and affective dimensions of reading self-concepts in English and Russian are distinct constructs and to examine whether the relationships among cognitive and affective variables are invariant across gender. A total of 349 tenth-grade Azeri students were selected from 12 schools in Baku, Azerbaijan. This study adapted the Self-Description Questionnaire and Cényelvi mérés for assessment of reading self-concepts and achievements in two foreign languages. The results of structural equation modeling demonstrated that cognitive and affective self-concepts were independent, but strongly interrelated constructs. The separated components of the reading self-concept construct showed a more explicit structure than a conflated model. The relationships among cognitive and affective self-concepts with achievements in the reading domain were invariant across gender. The results of this study can encourage future research on the examination of more domain-specific self-concepts that conceptualizes twofold multidimensional structure.