The concentration of high-density lipoprotein cholesterol and triglycerides in rat serum sharply decreased after psychic trauma caused by life hazard. The content of these substances remained unchanged for not less than 1 week after trauma. The concentration of high-density lipoprotein cholesterol was low, while serum content of triglycerides increased 6 weeks after trauma. The concentration of high-density lipoprotein cholesterol significantly decreased after repeated psychic trauma. These changes were accompanied by a sharp increase in the concentration of triglycerides in the serum. Total cholesterol concentration in the liver decreased under these conditions.