Formal and informal institutions emerge to constrain socially undesirable behavior emanating from interactions between individual and groups. Violence is one of such undesirable aspect of human interaction. Violence affects economy by deterring investment and destruction of infrastructure but its influence spills over many other aspects of national existence. This research aims to assess the role played by formal and informal institutions in mitigation or exacerbation of violence and to evaluate if incorporation of informal institutions affects the relationship between formal institutions and violence. Both political and societal violence is considered. Using crosscountry data from over 70 nations, instrumental variable regression is carried out to assess the impact of formal and informal institutions on various forms of violence. The results indicate that for political violence as a whole, ethnic violence, terrorism and homicides, informal institutions are more efficient in decreasing violence and also make formal institutions more effective, while civil war, inter-state wars and gender-based violence are more effectively prevented by formal institutional constraint, however, in the absence of informal institutions the formal institution become ineffective in mitigating violence. Supervisor:-Dr. Karim Khan