Alcohol appears to affect dolichol metabolism, as both serum and urinary dolichol concentrations were found to be significantly higher in alcoholics than in social drinkers. Furthermore, acute heavy drinking (5.5 g alcohol/kg body weight during 42 h) increased urinary dolichol excretion significantly, whereas moderate drinking (60 g/day for 10 days) had no effect. Increased urinary dolichol concentrations in alcoholics returned rapidly to normal with a half-life decay of 3 days, whereas increased serum dolichol concentrations did not change during a 7-day observation period. The mechanism behind alcohol-induced alterations in dolichol metabolism remains unclear, but based on our results, it seems likely that serum and urinary dolichols are regulated independently from each other.Key words: polyprenols, biological membranes, substance abuse, lysosomes.