The subjects were 20 chronic schizophrenic patients with dyslipidemia (total cholesterol levels greater than or equal to 220 mg/dl, triglycerides greater than or equal to 150 mg/dl, or high-density lipoprotein cholesterol less than or equal to 40 mg/dl) who had been receiving neuroleptics for a mean of ten years. Each patient was given 100 mg of gamma-oryzanol three times daily for 16 weeks. Total cholesterol and low-density lipoprotein cholesterol levels, respectively, decreased significantly, from 204 and 124 mg/dl at baseline to 176 and 101 mg/dl at week 12. High-density lipoprotein cholesterol levels were 36.1 mg/dl at baseline and 35.9 mg/dl at week 12. Apolipoprotein (apo) B levels decreased significantly from 116 mg/dl to 101 mg/dl at week 16; apo A-II levels increased significantly from 31.7 mg/dl to 34.7 mg/dl; and the apo B/apo A-I ratio declined significantly from 0.99 to 0.84. No treatment side effects were recorded. It is concluded that gamma-oryzanol is safe and effective in the treatment of dyslipidemia.