The activity of the extract ofHeliotropium filifolium, of the natural compounds obtained from its resinous exudates, filifolinol and fihfohnyl senecionate, and of the synthetic derivative of filifolinol, filifolinoic acid, on the mycehal growth of the phytopathogenic fungus Botrytis cinérea was analyzed in liquid and solid media. The extract of H'. filifolium, filifolinol, and filifolinoic acid reduced mycehal growth of this fungus. The effect of these compounds was dose-dependant. The compound fihfohnyl senecionate was inactive in all the tested conditions. The extract of H'. filifolium and filifolinol retarded the germination of conidia of the fungus