Mauritania has undergone massive economic and political changes. Mauritania is a West African country located on the western edge of the Sahara desert, with a population of approximately 3 million people that is mostly concentrated in the urban areas. Since independence in the 1960s, Mauritania's economy has been dependent on natural resources, iron ore first then combined with fisheries, and presently oil and other minerals. Natural resources exploitation and more recently oil discovery boosted Mauritania's rate of economic growth, but key challenges remain, in particular the promotion of productive value-adding activities and the creation of a strong, formal class of small and medium-sized enterprises (SMEs). The Government of Mauritania recognizes the strategic role of the private sector and the urgency of supporting SME development as a catalyst for long-term growth. In the Second Poverty Reduction Strategy Paper (GPRSP-II), the Mauritanian authorities indicated that accelerating economic growth will be based on: (i) optimizing spinoff effects from developing the oil business and implementing more effective policies for harnessing the growth potential of other promising sectors; (ii) a thorough reform of the financial system; (iii) significant improvement in the business climate and the development of SMEs; and (iv) giving a greater economic and land-use planning dimension to the infrastructure that supports growth (World Bank, 2006). Furthermore, the authorities identified several priorities to improve the business climate and promotion of SMEs, as follows: (i) improving the legal environment for businesses; (ii) fighting anti-competitive practices; (iii) making tax and customs policies more favorable to business; and (iv) institutional support for the development of trade and commerce. This country economic memorandum (CEM) examines the four most constraining factors to private sector development and proposes the formulation of practical solutions to enable the emergence of a strong class of formal private firms. Specifically, to accelerate growth and to attain the four strategic GPRSP II objectives - (i) optimize spinoff effects; (ii) reform financial system; (iii) improve the business climate and the development of SMEs; and (iv) improve business enabling infrastructure), the CEM analyses the role of taxation to promote firm formalization; skills development to enhance labor productivity; competition policy as a way to address anticompetitive market conduct; and the options for establishing special economic zones as instruments to close infrastructure gaps and promote investment climate reforms.