This study was undertaken to enable us understand the extent to which firms in the manufacturing industry in Nigeria, apply the marketing concept. Taking into consideration the country's large population, and large number of manufacturing firms which hinder on individual analysis of manufacturing firm as regards the application of the marketing concept, a case study of Sunglass Limited, Kaduna was undertaken. The consumer is the life-blood of the organisation, since if he does not buy, firm cannot sell and every firm that produces must sell to be in business. Therefore, the importance of the consumer to the achievement of corporate goals cannot be over emphasize. It is important, in order to achieve overall objective of the organisation, to strengthen and incorporate into the organisation the pillars of the marketing concept, that is consumer orientation and satisfaction, integration marketing effort, profit criterion and societal orientation. In our case study analysis of Sunglass Ltd, I found that the company is a marketing oriented enterprise. The consumer is the king is a watchword in Sunglass Limited and all marketing activities are planned around this concept. Sunglass Limited applies the marketing concept to a large extent, although some aspects of it are employed to the neglect of others.