Abstract: Biofungicidal composition from a biologically pure culture of a Chilean bacterial isolate obtained from soils of the seventh region of Maule, Chile, corresponding to Paenibacillus polymyxa SCHC33, strain with the deposit number RGM2141 granted by the depository authority of the Chilean Collection of Microbial Genetic Resources (CChRGM) to be used as an environmentally friendly, biological control agent against fungal plant diseases, particularly fruits susceptible to infection by Botrytis cinerea, efficiently inhibiting conidial germination and mycelium proliferation of said phytopathogenic fungus, furthermore protects plant leaves and fruits from infection by the same fungus, and has the potential to be used in biological control of other fungi and in general of phytopathogenic microorganisms.