Treatment with medicinal herbs dates back to the times before Christ and has been widely used all over the world for years. Today, its importance is increasing day by day and it is widely preferred because it is found more reliable. According to the World Health Organization, 20 thousand plant species are known in modern and traditional medicine. The number of plants used by the cosmetic and botanical industry is not included to the number. It takes many years to recognize a plant and use it in treatment and it is very difficult to protect it. Therefore, it is of great importance to recognize and develop the plants used in phytotherapy in the past. Paeonia L. (Paeoniaceae), known as "peony", is a perennial (geofit) plant with showy and attractive flowers and tubers under the ground. Paeoniaceae family is located in the rich flora of our country and has been used for their many medicinal effects. In this review article, peony species and their use in phytotherapy in Turkey and World were discussed with the studies on the subject.