The paper deals with the problems of the market economy that shape the efficiency of small and medium-sized businesses. The authors have conducted an overview of the history of the problem of development of small and medium-sized business institutions, identified their critical points, and evaluated the regional development of small and medium-sized businesses. An assessment of the current situation in the development of small and medium-sized businesses leads to the conclusion that entrepreneurship is no longer only an economic but also a social function of the realization of the public good. For an entrepreneur, his activity remains the realization of his talents, skills, and abilities, bringing the public good, rather than a profitable occupation. Groupings that show the degree of regional differentiation are used to assess the regional development of small and mediumsized businesses. The paper assesses the impact of COVID-19 on small and medium-sized businesses.