This paper takes a critical review on the causes of under-development in Sub-Saharan Africa. The study made use of qualitative research design in both data collection and analysis. In sourcing for data, the study made use of of both primary and secondary sources. The study argued that underdevelopment in Sub-Saharan Africa is caused by both internal and external factors. The external factors are the 400 years of slave trade, followed by the era of exploitative legitimate trade, colonialism and now neocolonialism. The period of neocolonialism in post-independent Africa has also witnessed massive economic exploitation through the instrumentality of the Bretton Woods institutions; the World Bank  and the IMF, WTO, and Multinational Corporations. These neocolonial interest had overtime used subtle means to manipulating these weak and vulnerable economies through different strategies such as development aid and loan conditionality. The loan conditionality includes, trade liberalization, privatization, removal of subsidies, financial deregulation, technical assistance etc. Thus,  further deepening the dependency and the underdevelopment of these poor countries. The internal factors responsible for Sub-Saharan African development crisis includes, the underdeveloped productive forces, leadership failure, infrastructural deficit, weak institutions, lack of economic integration, underdeveloped agriculture and the manufacturing sectors etc. The study further argued that after almost a century of political independence, the blame game on the external factors been responsible for Africa’s development crisis,  no longer holds water but rather the internal factors are more responsible for Africa’s underdevelopment. This is evident in the economic prosperity been witnessed by the economies of the Asian Tigers like Malaysia, Singapore, Taiwan, Hon kong who also went through the same colonial experience and was incorporated in to the global capitalist system but yet, today they are been classified as emerging economies with impressive HDI due to massive industrialization and economic development. This  further debunk the long held claim by the Dependency theorists.