Etiroxate is a synthetic thyroxine derivative. It was used for the treatment of patients with hyperlipoproteinaemia. There were only slight side effects, such as gastric and autonomic nervous system symptoms. No statistically significant increase in anginal symptoms was found, even in patients with known coronary insufficiency. No negative effects on hepatic and renal function or the peripheral blood count were observed. Etiroxate caused a significant reduction in serum cholesterol, LDL-cholesterol, and serum apolipoprotein B. There was a significant decrease in HDL-cholesterol. Etiroxate might be used for the treatment and prevention of atherosclerotic disease.