Four mutualistic endophytic fungal isolates were investigated for their ability to induce systemic resistance in banana toward the burrowing nematode, Radopholus similis in glasshouse experiments. Two isolates of Fusarium oxysporum and one of F. cf. diversisporum isolated from the cortical tissue of banana, and another isolate of F. oxysporum isolated from tomato, were compared. When the root systems of seedling banana plants were pre-inoculated with the four endophytic fungi, R. similis root penetration was reduced by 29-39% and 22-41% 5 and 15 days after nematode inoculation, respectively. Induction of systemic resistance to R. similis in banana roots by the same endophytic fungi was tested in a split-root system. Depending on the isolate, the penetration rates decreased between 30-38.5% and 26.7-45% after 5 and 15 days in the untreated half of the split-root system of plants treated with the endophytic strains when compared to those treated without the fungi. This is the first time that systemic resistance induced by a fungal endophyte has been demonstrated in banana.