Abstract The effect of diethyl maleate treatment, fasting, and time of administration on allyl alcohol hepatotoxicity was investigated. Allyl alcohol given to fed animals at 21.00 h resulted in a marked elevation in plasma enzymes. Fasting protected against and diethyl maleate treatment potentiated the toxicity of allyl alcohol. Administration of allyl alcohol to either fed or fasted animals at 09.00 h caused no increase in plasma enzymes. These results suggest that glutathione as well as NAD + /NADH ratios are important factors in allyl alcohol hepatotoxicity.