Colonization, an imperial conquest of native lands by European countries, became an epoch-making, monumental highlight in the historical development of third-world countries. There is no gainsaying that the colonial exercise did more evil than good for the colonized world. The decolonization of Africa and other colonized areas of the world was a slow process that was triggered by the First and Second World Wars. The devastating effects of the two wars on the economies of the West, coupled with the native resistance from the colonies, made colonialism impracticable. Hence, the European imperialist states were faced with no other choice than to relinquish their dominance in their colonies. Nigeria, which finally, attained independence in 1960, tailored its national development policy along the welfarist paradigm. In 1987, Nigeria joined the rest of the world in subscribing to the ideology of sustainable development by partaking in the World Commission on Environment and Development summit. The realization of the Sustainable Development Goals (SDGs) became entrenched in national developmental planning after Nigeria attended the Sustainable Development Conference held by the UN in 2012. However, following the years of decolonization, Nigeria has grappled with developmental challenges and appeared to be in reverse gear in the developmental process. The post-colonial upheavals and mismanagement of Nigeria became a glaring feature, thus having far-reaching consequences on her development strides. This begs the question as to what and how the decolonization exercise benefitted Nigeria. Therefore, this study examines the decolonization dilemma of Nigeria and how it has hampered Nigeria’s chances of attaining sustainable development. The study employed a qualitative and expository analysis in examining the effect of the decolonization process on the attainment of the SDGs. The study builds on data from a range of published and unpublished sources. It was concluded in the study, that the climate that arose from the decolonization process had not enhanced the actualization of sustainable development in Nigeria. Among the suggestions in the study includes retracing the decolonization steps taken thus far and redefining how Nigeria can be rid of the legacies and traces of colonialism so as to set out on a steady drive toward attaining sustainable development.