Familial homozygous hypercholesterolemia is characterized by markedly increased cholesterol levels ranging between 600 and 1200 mg/dL and premature atherosclerotic morbidity and mortality. Various dietetic, medical, and surgical therapeutic regimens have been tried, with limited success. Herein we describe two women homozygous hypercholesterolemic patients born in 1962 and 1971, who underwent intermittent-flow plasma exchange at three-week intervals for almost two years. A marked decrease was observed in skin and tendon xanthomata, and the cardiac status of the patients remained stable. The older patient, who had effort angina pectoris prior to plasma exchange, became symptom-free after one year of treatment. The procedure was well tolerated with no major side effects. We conclude that plasma exchange is an effective treatment for familial homozygous hypercholesterolemia and should be initiated as early as possible, prior to the appearance of atherosclerotic end-organ damage.