"Theories of Underdevelopment" primarily focuses on the socio-economic factors that contribute to underdevelopment, with a particular emphasis on Latin America. The book employs a sociological perspective to explore various theoretical frameworks, including modernization and dependency theories, to explain the persistent gap between developed and developing nations.

Ian Roxborough critiques modernization theories by highlighting their limitations and arguing that they often overlook the unique socio-economic and historical contexts of developing nations. He challenges the assumptions of these theories and encourages a more nuanced understanding of development that takes into account the specific circumstances of each nation.

"Theories of Underdevelopment" offers alternative perspectives by examining dependency theory and the internal dynamics of developing societies. Roxborough explains how historical and contemporary relationships between developed and developing nations contribute to ongoing reliance and exploitation. He also investigates internal factors such as social structures, rural class relations, and political systems, providing concrete examples of peasant movements and revolutions to illustrate the diverse ways in which societies strive for social and economic justice.