The in vitro activity of the silver nitrate was assessed in comparison with that of natamycin against 128 corneal Fusarium isolates and 90 corneal Aspergillus isolates. MIC(90)s of silver nitrate were 2 microg/ml for Fusarium spp. and 1 microg/ml for Aspergillus spp. MIC(90)s of natamycin were 8 microg/ml for Fusarium spp. and 32 microg/ml for Aspergillus spp. Silver nitrate exhibited potent antifungal activity against ocular fungi in vitro.