This article presents the results of a study of the state of entrepreneurial activity in the Rostov region. In accordance with the procedure and methodology of statistical accounting of the Federal State Statistics Service, fast-growing enterprises are singled out as part of active enterprises, including gazelle enterprises and mouse enterprises. "fading" enterprises are also considered separately. The enterprises of the greatest research interest are gazelles - a subgroup of fast–growing enterprises whose age does not exceed five years, with an average annual increase exceeding 20% per year over a three-year period. It is on the basis of this category of active enterprises that the bulk of the increase in value added and the number of new jobs created is formed. The article presents a dynamic and structural analysis of active enterprises in the Rostov region as a whole, as well as with an emphasis on diagnosing the potential and development trends of gazelle enterprises. Conclusions are drawn regarding the state and prospects of the development of the business sector in the region, recommendations are given to the executive authorities in terms of assistance and increasing support for fast-growing companies. In Russia, a number of measures are currently in place at the federal level to support domestic private high-tech and fast-growing companies. But at the regional level, on the basis of a systematic approach, fast-growing companies are not supported. The main conclusions of this article can be taken as a justification for the need to develop an appropriate regional policy to support gazelle enterprises.