A case of type III hyperlipoproteinemia (HLP) (dysbetalipoproteinemia) acquired by liver transplantation is reported. The 50-year-old female patient was referred to the Frankfurt University Hospital for orthotopic liver transplantation. She had suffered from ethylic liver cirrhosis. The donor liver showed discrete signs of steatosis. The postoperative course of the patient was satisfactory. Enzyme levels and blood coagulation tests returned to normal within thirty days. However, both cholesterol and triglycerides gradually increased from approximately 2.00 g/L to values ranging from 2.50 to 3.50 g/L within 200 days after transplantation. Cutaneous xanthomas did not develop. The patient's lipoprotein pattern met the criteria of type III HLP: the cholesterol to triglyceride ratio in very low-density lipoproteins (VLDL) was 0.64. Intermediate-density lipoprotein(IDL) cholesterol was 0.48 g/L. Lipoprotein electrophoresis showed a broad beta-band, and beta-migrating particles were present in VLDL. Immunoblotting of apolipoprotein (apo) E from the patient's plasma revealed an E2/2 phenotype. However, restriction isotyping of an in vitro amplified apoE gene fragment showed the genotype of the patient to be epsilon 3/epsilon 4. These data suggest that the development of type III HLP in this patient was due to a change in the apoE phenotype from E3/4 to E2/2 after liver transplantation.