The Tronosa Forest Reserve is located in the province of Los Santos, Tonosi district with an area of 20.579 ha. The aim of the research was to determine the use of medicinal plants. The methodology includes surveys ethnobotanical walks and implementation in communities: La Bijagual, Culebra, Corotua and La Bonita. Species were identified 108 and 1855 data source and used portion of the plants, the preparation form and processed healing properties. La Bonita was the community that uses the medicinal plants by 38%. The part of the plant used was the leaf (69%) and are prepared in wash (65%) and tea (57%). The plants most commonly used are aloe, mastranto and sage. The most common diseases are respiratory (19,7%), body pain (19%) and stomach problems (18%).