Siderophores are low molecular weight (<1000 D) iron chelating compounds produced by microorganisms. Production of siderophore is a device of antagonism as by virtue of the capacity of siderophore production, a microorganism competes for Fe (III) with the others. Production of siderophores by 9 different soil fungi and wood-decay fungi was studied following CAS - assay and CAS - agar plate assay. Optimization for the production of siderophores was done by varying the levels of pH and Fe (III) concentrations in the low nutrient medium. All the test fungi could produce siderophores, though the degree of production recorded to be very low both in Botryodiplodia theobromae and in Fusarium spp. On the other hand, all the species of Trichoderma showed their excellency in siderophore production. The optimum pH for production of siderophores remained at neutral pH level though the range varied from pH 6.0-8.0. The optimum range of the concentration of Fe (III) required for siderophore production was recorded to be 1.5-21.0 µM. However, the stress condition of iron might be a decisive factor for siderophore production.