We have studied polymorphism of apolipoprotein E (apoE) phenotype in sera from 100 patients with psoriasis vulgaris and 100 healthy controls. The phenotypes of apoE were determined by isoelectric focusing, which was followed by immunoblotting using an antibody specific for apoE. The frequency of apoE3/2 in psoriatic patients was significantly higher than those in controls. In addition, the statistical analysis revealed that there was an association between the allele for apoE2(ε2) and psoriasis vulgaris ( Pc<0.05 ).