Background: For over a hundred and fifty years, consecutive Ethiopian regimes have perpetuated collective violence against the Oromo people. During those years, the Oromo people have been denied their collective rights i.e. the right to decide on their social, economic, political, cultural and environmental affairs. Objectives: In this paper, I explore the ways collective violence and the denial of the collective right of the Oromo people has hindered the development of better public health conditions. Methods: In this paper, using the WHO definition of health as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity" and collective violence as "the instrumental use of violence by people who identify themselves as members of a group, whether this group is transitory or has a more permanent identity, against another group or set of individuals, in order to achieve political, economic or social objectives" as the framework of thinking explore the relationships between collective violence and the under-development of public health conditions. Finding: The core functions of public health are assessing social conditions that contribute to health and diseases, developing healthy policies, widening people's choices in life and assuring their implementation. The optimum development of public health can be achieved if societies continuously strive to prevent diseases through the promotion of healthy social policies. Collective violence and the violation of collective rights hinder the social, economic, political, cultural and environmental capacity of the Oromo people. This impairs the development of public health. Conclusion: Collective violence and the violation of collective rights are profoundly contrary to the objective of a public health agenda. The prevention of collective violence and promotion of collective rights should be seen as an essential condition necessary to the development of the social, economic, political, cultural and environmental capacity of the Oromo people and the development of public health conditions.