Keywords: Sclerotinia minor , Sclerotinia sclerotiorum, Trichoderma asperellum, Trichoderma asperelloides, Lactuca sativa, controle biológico, controle químico.Lettuce drop, caused by Sclerotinia sclerotiorum and S. minor, is considered one of the most important diseases that affect this crop in Brazil (21); it is also widespread worldwide, causing considerable losses in lettuce crops (22).This disease causes wilting and collapse of lettuce heads in infested fields where weather conditions favorable for its development, such as mild temperatures and high humidity, prevail (13, 28). The main difference between S. sclerotiorum and S. minor is that the latter forms a white mycelium with several small black sclerotia (0.5 to 3 mm diameter), while S. sclerotiorum forms fewer and larger sclerotia, irregular in size, on the lettuce heads (28).The management of lettuce drop is usually obtained by integrating Lettuce drop, caused by Sclerotinia minor and S. sclerotiorum, is one of the most important diseases that affect lettuce crop in Brazil. In previous studies, isolates of Trichoderma asperellum (IBLF 897, IBLF 904 and IBLF 914) and T. asperelloides (IBLF 908) were selected for the biocontrol of this disease. In this subsequent study, the compatibility of these isolates with pesticides used in lettuce crop in Brazil was evaluated. Initially, the mycelial growth of isolates was evaluated in culture medium plus pesticides. Then, the effect of pesticides on the parasitism of T. asperelloides isolate IBLF 914 in baits and sclerotia of S. minor and S. sclerotiorum, as well as on the survival of lettuce seedlings, was evaluated in gerboxes after application on baits and sclerotia of the antagonist with pesticides at their respective commercial doses.