Recent research suggests that traditional grain-based heart-healthy diet recommendations, which replace dietary saturated fat with carbohydrate and reduce total fat intake, may result in unfavorable plasma lipid ratios, with reduced high-density lipoprotein (HDL) and an elevation of low-density lipoprotein (LDL) and triacylglycerols (TG). The current study tested the hypothesis that a grain-free Paleolithic diet would induce weight loss and improve plasma total cholesterol, HDL, LDL, and TG concentrations in nondiabetic adults with hyperlipidemia to a greater extent than a grain-based heart-healthy diet, based on the recommendations of the American Heart Association. Twenty volunteers (10 male and 10 female) aged 40 to 62 years were selected based on diagnosis of hypercholesterolemia. Volunteers were not taking any cholesterol-lowering medications and adhered to a traditional heart-healthy diet for 4 months, followed by a Paleolithic diet for 4 months. Regression analysis was used to determine whether change in body weight contributed to observed changes in plasma lipid concentrations. Differences in dietary intakes and plasma lipid measures were assessed using repeated-measures analysis of variance. Four months of Paleolithic nutrition significantly lowered (P < .001) mean total cholesterol, LDL, and TG and increased (P < .001) HDL, independent of changes in body weight, relative to both baseline and the traditional heart-healthy diet. Paleolithic nutrition offers promising potential for nutritional management of hyperlipidemia in adults whose lipid profiles have not improved after following more traditional heart-healthy dietary recommendations.