Concerns about toxicity of cholesterol oxidation products (COPS) prompted this study. Two restaurants were selected which use animal-vegetable (A/V) shortening for deep-frying. The survey of COPS for 30 days indicated values for total COPS in French fried potatoes were 20 ± 9 ppm to 24 ± 6 ppm. 5α-Cholestane-3β,5,6β-triol (triol) was identified in French fried potatoes from one restaurant. The mean for triol was 9 ± 3 ppm. Triol, 7α-hydroxycholesterol, 7β-hydroxy-cholesterol and 7-ketocholesterol were confirmed by co-chromatography and mass spectrometry. Triol is one of the most potent of angiotoxic COPS. This and other studies suggested French fried potatoes and other deep fried foods cooked in A/V shortening are a major source of COPS.