Fourteen phyllosphere organisms (ten fungal and four bacterial) were isolated from the healthy leaves of sunflower (cv Morden). Most of the fungi isolated belonged to the genus Aspergillus. The in vitro evaluation of culture filtrates of these organisms on uredospore germination of P. helianthi revealed the presence of antifungal activity in the culture filtrate of all the organisms, however it varied with concentrations of the culture filtrate and organisms. The organisms found effective under in vitro were further tested in vivo. The mixed inoculation of pathogen and antagonist significantly reduced the number of uredia per square centimeter (MNUC).