Cafestol, a coffee diterpene present in unfiltered coffee brews, potently raises serum lipids in humans. The mechanism through which this dietary compound influences lipoprotein metabolism is largely unknown. Unravelling the mechanism of action might lead to new insights into the regulation of serum cholesterol levels in humans. This review summaries ways in which cafestol may act on serum lipids. Curr Opin Lipidol 10:41-45. (C) 1999 Lippincott Williams & Wilkins.