Rhizoctonia solani, a phytopathogen that causes “damping off”, affects all plants that are propagated by botanical seed in the germination and seedling phases. The objective was to evaluate the mycoparasitic activity of nine isolates of different Trichoderma strains on Rhizoctonia solani, using Cowpea beans (Vigna unguiculata L). The isolates were 'T20, T17, T9, T10, TSV2, TSV, T10’ from Trichoderma asperellum; T5 from Trichoderma viride and T327 from Trichoderma harzianum. A treatment only with Rhizoctonia solani was considered, as a virulence control and a treatment only with Cowpea beans as a control of the viability of the seed. The treatments were arranged in a complete randomized design with 10 repetitions. The dual confrontation technique was used in a potato-dextrose-agar (PDA) culture medium in a Petri dish, considering the experimental unit. Samples were taken from the co...