Production of Indole-3-Acetic Acid by three species of Seimatosporium (S. falcatum, S. fusisporum and S. discosioides) causing stem canker and dieback of Eucalyptus tereticornis was investigated. Though all the three species of Seimatosporium under investigation produced Indole-3-Acetic Acid, degree of production varied with the species, medium and incubation period. Indole-3-Acetic Acid production by all the three species was more in medium containing complex nitrogen source. S. discosioides produced comparatively more amount of Indole-3-Acetic Acid than other two species. No positive correlation could be observed among mycelial growth, Indole-3-Acetic Acid production and pH of the medium.