ABSTRACT This study evaluates the deregulation of the downstream sub-sector of the petroleum industry. This study arose out of the need to find solution to the sorry state of the four refineries, the inefficiency in the distribution, the poor pricing of petroleum products and the negative effects of monopolistic structure of the downstream sub-sector. The study attempt to identify the challenges associated deregulation of the downstream sub-sector and to examine the effects of deregulation of the downstream sub-sector on petroleum product pricing in Nigeria. The study examine the extent to which deregulation has impacted on availability of petroleum product since 2003. The study progressed to identify what policy options are there for improved performance in Nigerian downstream subsector. The descriptive survey research design was used and data was collected using questionnaire method. Chi-square and simple statistical methods was used for data analysis. The findings of the study amongst others review deregulation of the downstream is to open the market for new investors and reduce government spending on subsidy payment. It is recommended that government need to create an enabling environment for private individuals and companies to establish refineries and should double the quantity of crude for domestic refining needs, in this way, the country should target supplying the refined needs of these would be investors.