A randomized, double-blind, placebo-controlled, crossover clinical trial was designed to test the efficacy of psyllium fiber in lowering elevated low-density lipoprotein cholesterol (LDL-C) levels in children 5 to 17 years of age. Subjects with LDL-C levels > 2.84 mmol/L (110 mg/dl) after at least 3 months of a low total fat, low saturated fat, low cholesterol diet were enrolled. Two ready-to-eat cereals, with water-soluble psyllium fiber (6 gm/day) and without, were prescribed for 4 to 5 weeks each, with an intervening 2-week washout phase. Reported compliance rates exceeded 80% in the 20 subjects who completed the study. Mean initial total cholesterol, LDL-C, high-density lipoprotein cholesterol, and triglyceride values were 5.23, 3.60, 1.18, and 2.22 mmol/L, respectively. Comparison of the mean changes (from baseline) in lipid values after the two periods of cereal consumption revealed no statistically nor clinically significant differences in total cholesterol, LDL-C, or high-density lipoprotein cholesterol values. Triglyceride levels, however, increased 0.68 mmol/L (26 mg/dl; p < 0.05) after the control cereal in comparison with the psyllium cereal. No significant differences were noted in the children's dietary intake (assessed by 7-day diet records) during the two study periods. Measures of growth (height, weight, and skin-fold thicknesses), and blood vitamin (folic acid; vitamins A, D, and E) and mineral (iron, zinc, and calcium) levels were not affected. In this study, psyllium fiber had no additional lowering effect on total cholesterol or LDL-C levels in children who were already following low total fat, low saturated fat, low cholesterol diets.