The objective of this study was to evaluate the antagonistic effects of two native isolates of Trichoderma asperellum (GRB-HA1 and GRB-HA2) against the phytopathogenic fungi Colletotrichum gloeosporioides, Curvularia lunata, and Fusarium oxysporum, with the aim of developing biological control agents to replace the use of chemical fungicides. An antagonism assay was performed under in vitro conditions using the dual culture method, and the percentage inhibition of radial growth (PIRG) and the degree of mycoparasitism (grade 0-4) were evaluated after 10 days of culture. Results show that both isolates resulted in 100% PIRG and grade 4 mycoparasitism in dual cultures against Colletotrichum gloeosporioides and Curvularia lunata although GRB-HA1 led to 70% PIRG and grade 3 mycoparasitism and GRB-HA2 led to 84% PIRG and grade four mycoparasitism against F. oxysporum. Thus, these native T. asperellum isolates show potential for the biological control of diseases caused by phytophathogenic fungi.