In short-term experiments, healthy fasting persons were given a basic dose of 0.5 g of ethanol/kg body weight, followed by hourly maintenance doses of 0.15 g of ethanol/kg body weight. After 10 h there was a significant increase of triglycerides in the VLDL, LDL, and HDL, the main rise (from 42 to 92 mg/dl) being found in the VLDL triglycerides. Other subjects, who received nourishment isocaloric with ethanol, likewise showed a significant rise of triglycerides in all lipoprotein fractions. Chylomicron triglycerides increased from 9.3 to 35.5 mg/dl. There was no significant change in postheparin HTGL, but postheparin LPL activity decreased after 10 h from 17.9 to 12.2 mmol FFA/ml/h in the fasting subjects, and from 28.5 to 10.2 mmol/FFA/ml/h in the persons receiving food. In long-term experiments after 4 weeks of 70 - 80 g of ethanol and isocaloric food daily, triglycerides increased, especially in the VLDL (from 50 to 82 mg/dl). The increase in the HDL, however, was also significant. After 4 weeks of ethanol, the chylomicron triglycerides in the plasma of the fasting subjects reached a value of 29.3 mg/100 ml, LDL cholesterol decreased, and HDL cholesterol increased. After 4 weeks of ethanol there was an increase in the lipoprotein lipase of the adipose tissue.