Can general criminological theories of crime explain mass participation in genocide? Can seemingly conflicting theories be reconciled? And, if so, how? Only a small number of studies have attempted to explore the application of general criminological theories to international crimes. Also, there have been few attempts to integrate micro-level theories with macro-level theories. In this paper, I propose a macro–micro integrated theoretical model of mass participation in genocide. The proposed framework combines micro- (e.g. social control theories) and macro-level theories (e.g. strain theories), thereby recognizing that no single factor can explain people’s involvement in genocidal violence perpetration. Finally, the central element of my conceptual framework is the notion of cognitive dissonance (CD). I contend that CD can act as a structuring concept which allows for the development of a comprehensive criminological explanation for mass participation in genocide.