The article presents a study of today’s market of medicinal plants in Ukraine. It was discovered that the world’s demand for both medicinal plants and herbal medicines is rapidly growing.Today production of medicinal plants is a promising and profitable activity. The purpose of the article is to research the level of concentration and to determine the leading medicinal plant growers in Ukraine, as well as to assess risks of collective monopolization of Ukrainian medicinal plants market.?Object of the research –a pool of enterprises-producers of medicinal plants in Ukraine, according to official statistics. The assessment of medicinal plants market concentration was carried out using the following coefficients (indices): concentrationratio, Linda Index, Herfindahl–Hirschman Index, relative concentration, entropy index, market share dispersion among leading firms, variation index, Gini index, Hall-Tideman index. In order to clearly demonstrate the level of uneven distribution of medicinal plants in the market between the leading producers Lorenz Curvewas built. The assessment of Ukrainian medicinal plants market concentration and monopolization showed the signs of limited oligopolypresence. The analysis of oligopolynucleus dispersity, which determines the ratio between the sizesof individual firmscomposing it, showed the uneven distribution of market shares between enterprises-competitors. Further detailed research of the medicinal plants market will make an important contribution tothe market strategy development of this sphere in Ukraine.