The effects of moderate alcohol intake on the lipoprotein profile were evaluated in 10 normolipemic abstinent male subjects aged 18-21 years. The experimental period lasted 4 weeks during which 30 g of alcohol were ingested daily as red table wine. It was preceded and followed by 3 weeks of total abstinence. Lipoproteins were analyzed by gradient ultracentrifugation at the end of each abstinence period and weekly during the experimental period, to follow the time-course of alteration. Total HDL were increased by 25% (range 14-72%) during the first 2 weeks of alcohol, lighter HDL3, but not HDL2, exhibiting a greater response than other classes. The effect of alcohol regressed with time and by the 4th week mean HDL levels were only 14% higher than prior to treatment. HDL levels returned to normal on weaning. The wide variations in individual responses were consistent over the experimental period and are suggestive of differences in individual susceptibility.