Evaluation of the association of 8-hydroxyquinoline with commercial fungicides against phytopathogenic fungi where it was possible to verify the synergism between the compounds and the antifungal, which led to in vivo tests using rice seeds. The association of 0.5 g/L of mancozeb and 0.031 g/L of 8-hydroxyquinoline, concentration 4 and 8 times lower than the one usually used, respectively, was promising. The test of leukocyte cytotoxicity and dermal toxicity was carried out, showing, in view of all the tests performed, a potential selective agent against variations of Fusarium graminearum and Fusarium meridionale in rice seeds.