The influence of sex steroids on the serum lipoprotein pattern was recognized more than 30 years ago, and it still remains among the areas of major interest. This is because of the compatible sex difference in plasma lipoprotein pattern and in coronary heart disease risk. Recent discoveries of the role of hepatic lipase in lipoprotein metabolism have elucidated mechanisms behind sex steroid-induced changes in lipoproteins. These steroids regulate the activity of hepatic lipase, an enzyme bound to the endothelial cells of liver sinusoids. Hepatic lipase has a central role in the removal of phospholipids and triglycerides from subfractions of high-density lipoprotein (HDL2) particles, but it may also function in the lipolysis of triglyceride-rich particles. Some older and more recent developments in this area will be reviewed.