Cyclosporin is a fungal metabolite with antifungal activity and powerful immunosuppressive properties, useful in organ transplantation. It was originally isolated from Trichoderma polysporum, and many soil fungi have been found to produce it since then. Previously, cyclosporin A and an N-acetyl "C9-amino acid" were isolated from Neocosmospora vasinfecta var. africana NHL2298, and cyclosporin production by N. vasinfecta var. vasinfecta was reported but without specifying yields and chemical properties. In continuing studies on metabolites of other Neocosmospora spp. strains, we found some strains produce cyclosporin A, and strain IFO 8966 produces cyclosporin C as a major antifungal metabolite. This paper reports cyclosporin production by some Neocosmospora spp. strains. Eight Neocosmospora strains were tested for antifungal metabolite production against Alternaria kikuchiana via bioassay, revealing IFO 8966, 31377, and NHL 2919 produce such metabolites. These strains were stationarily cultured on malt extract medium with 3% peptone at 24°C for 21 days. Cyclosporin A was isolated from the culture filtrate of IFO 31377 (0.78 mg/l) and mycelial mats of NHL 2919 (19.0 mg/l). Monorden was also isolated as an antifungal metabolite. The major active compound from IFO 8966's mycelial mats (1.7 mg/l) was identified as cyclosporin C via 1H/13C NMR, FABMS, amino acid analysis, and comparison with literature data. HPLC analysis showed IFO 8966 mainly produces cyclosporin C, while NHL 2298 is the only strain secreting N-acetyl "C9-amino acid". These fungi may serve as good tools for studying the biosynthesis of cyclic peptides like cyclosporins.