Levels of cholesterol oxides were determined in samples of beef dripping used for deep frying in retail fast-food outlets in Christchurch, New Zealand. The average levels (n = 8) of cholesterol oxides were: beta-epoxy cholesterol (is mg/kg), alpha-epoxy cholesterol, 7 beta-hydroxy cholesterol, 7-keto cholesterol (10 mg/kg each), 7 alpha-hydroxy cholesterol (5 mg/kg), and cholestane triol, 25-hydroxy cholesterol (1 mg/kg each). Based on the amount of fat in a typical deep-fried ''fish and chips'' meal, the amounts of individual cholesterol oxides consumed would then range from 0.05-0.7 mg. This is three to nine times less than reported in a test meal experiment with humans but could still be expected to cause detectable increases in plasma cholesterol oxide levels.