The study examines the impact of trade liberalization on manufacturing value-added in Nigeria between 1970 and 2014. Basically, the study employed the tools of quantitative empirical analysis technique to evaluate the impact of trade openness on the output of Nigerian manufacturing sector. Findings from the study reveal that the Nigerian economy has not changed its export structure over the 1970 - 2014 periods. The only changes that have taken place to its exports were just a mere shift in exported product indicating a sign of export substitution from primary agro industry-based exports to primary mining industry-based exports (i.e crude oil). It should be noted that heavy reliance of the Nigerian manufacturing firms on imported machinery and equipments is a reflection of the weak manufacturing base of the country .Also it can be adduced from the study that the inability of the Nigeria manufacturing sector to respond positively to the export potentials inherent in trade liberalization may be due to high cost of production in the country that put our manufacturing output in a disadvantageous position in international market. Generally, enough incentives for efficient resource allocation in order to promote manufactured exports within the on-going process of economic liberalization and deregulation paradigms have not been created. It was proposed that a mixture of the invisible hand of the market with the visible hand of the state should guide the process of manufacturing activities, economic diversification, trade and development similar to the case of the East Asian Tigers.