In the modern context, “underdevelopment” refers basically to the difference between societies that have and those who have not, or have to a lesser degree. This definition sounds vague, but identifying a universal way of defining the difference between a developed society and an underdeveloped one is tricky. In attempting to analyze the causes of underdevelopment, there are two main classes of explanation: the reasons why a given nation did not develop industrially to begin with, and the reasons why a nation remains underdeveloped at the present time and does not proceed with development or industrialization. This paper examines the possible root causes of underdevelopment and its theories.