The effect of a 53% oat bran diet and a 30% pinto bean diet on hamster plasma total cholesterol (TC) and triglycerides (TG) was investigated. Hamsters were made hypercholesterolemic (average value = 206 mg/dL) and then fed one of four experimental diets, the hypercholesterolemic control (HC), an insoluble fiber (alphacel) control (FC), the oat bran (OB), or the pinto bean (PB) diet for three weeks, with the latter three containing 8.5%, 10.0%, and 7.6%, total dietary fiber, respectively. Plasma TC and TG were measured for each animal before and after the experimental diets. At the end of the experimental period, plasma TC levels of hamsters fed the OB diet (179 mg/dL) were significantly lower than those fed either the HC (203 mg/dL, p<0.05) or FC (221 mg/dL, p<0.001) diets. Plasma TG levels of hamsters fed the OB diet (200 mg/dL) were significantly lower than those fed the FC diet (358 mg/dL, p<0.01). Thus, it was concluded that oat bran significantly lowered plasma TC and TG in hypercholesterolemic hamsters, while pinto beans did not.