This chapter summarises some of the barriers to local SMEs accessing the procurement opportunities in the supply chains of oil, gas and mining companies. Different definitions of small- and medium-scale enterprises (SMEs) abound, from unregulated micro firms in the informal sector, to what in poorer economies would constitute large companies employing hundreds of people. For governments, whether in developed or developing countries, the SME sector is often viewed as a key driver for employment creation and technology innovation. In developing economies especially, a second critical barrier to SME participation in procurement is the market power influence of the larger, established suppliers. The challenge, then, for either industrial policy-makers or private procuring companies is first to identify who these high-growth SMEs are, and then provide them with appropriate support to unleash their full potential. The role of procurement procedures in supporting or constraining the participation of high-growth local SMEs in the supply chains of oil, gas and mining companies is discussed.