The lack of adequate education for entrepreneurship of small and medium-sized enterprises (SMEs) executive managers and owner-managers in Nigeria increases the high rate of poverty and unemployment. Lack of management training and experience contributes to 69% of SMEs' failures. Research on entrepreneurial development and agency intervention for business growth lacks criteria specific to adequate entrepreneurial education for business growth and sustainability. The inadequacy in teaching entrepreneurship education encumbers Nigerian national development. The problem is that entrepreneurs in Nigeria lack adequate education in entrepreneurship and business sustainability. The exploratory case study addressed gaps and paucity in previous literature on why Nigerian SMEs lack adequate education for entrepreneurship and business sustainability. Ten entrepreneurs were interviewed to explore how to apply education to operate businesses strategically for growth and sustainability. Data analysis and interpretation revealed four themes: (a) inadequacy of entrepreneurship education and capacity building; (b) lack of a strategic management approach for competitive advantage; (c) lack of business leadership, orientation, and experience; and (d) unsustainable business strategy for sustainability and growth. The research findings provide entrepreneurs strategic management approaches to achieve efficient business development for business growth and sustainability. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]