Various governments all over the world have acknowledged that entrepreneurship and the formation of micro, small and medium enterprises is the key to economic growth, employment generation and poverty alleviation. However, for entrepreneurship to play this role effectively and efficiently, it must be a vital and an integral component of productivity and growth. Most SMEs in Nigeria experience abysmally low performance, and some even fold up within five years of start-up despite governmental efforts in encouraging entrepreneurial development in the country, This work on the importance of marketing in entrepreneurial development and poverty alleviation in Nigeria aims at identifying the sources and causes of problems in the orientation and practice of entrepreneurship and marketing in SMEs. The paper is a conceptual study and as such relied more on the review of the views of different scholars and researchers in marketing, entrepreneurship and SMEs in Nigeria and elsewhere. The study revealed that most SMES in Nigeria needed more exposure to the principles and practice of marketing and entrepreneurship so as to contribute maximally to economic development, employment and poverty alleviation in the country in spite of the ever-increasing competition both locally and internationally. To achieve this, the study recommended, among others, that the entrepreneurial and marketing skills of budding entrepreneurs and chief executive and directors of SMEs. Should be enhanced through education and training. This can be achieved through either formal regular education for those who can afford it, or by some part-time arrangements with professional marketers, and university lecturers as consultants.