Fulvia fulva, the agent of leaf mould, is known to be a major parasite of tomato leaves in greenhouses. Its development is characterized by a biotrophic phase followed by a necrotrophic phase. Hansfordia pulvinata is a hyperparasite of this pathogen, but its destructive action is restricted by its inability to colonize F. fulva during the biotrophic phase, before lesion formation. An integrated system to optimize the mycoparasitic activity of H. pulvinata was studied. The hyperparasite was tolerant to fosetyl-Al in situ. At a minimal concentration of 500 mg/L, the fungicide inhibited F. fulva spore germination after spraying on tomato leaves but did not have any effect during the necrotrophic phase. Thus, fosetyl-Al, which prevented reinfection, and the destructive hyperparasite H. pulvinata had complementary effects. Key words: Hansfordia pulvinata, fosetyl-Al, Fulvia fulva, integrated control, leaf mould, tomato.