A fungal culture isolated from a local soil sample which showed antifungal activity and produced cyclosporin A, was identified as Tolypocladium inflatum. The culture grew best in a medium containing 1% maltose (pH 5-6) when inoculated with a one-day-old inoculum at 2% (V/V) concentration. Under batch fermentation conditions, growth and cyclosporin A production were better in complex media (24.6 g biomass and 205 mg cyclosporin A per liter) in comparison with synthetic media (6.84 g biomass and 35 mg cyclosporin A per liter). While addition of peptone increased culture growth (high biomass yield), supplementation with casein acid hydrolyzate favored cyclosporin A production.