Metronidazole infusion was sterilized in an autoclave at 122°C for different values of F0 up to 65.3 min. Both metronidazole degradation and the Production of nitrite ion correlated with F0. A typical sterilization cycle of approx. 121°C for 15 min. is likely to lead to 1.5-2% loss of metronidazole and the production of 1.5 ppm nitrite. The yield of nitrite was only 3-9% of the metronidazole destroyed.