Apolipoprotein E (apoE) is the major brain apolipoprotein, and is related to the functional integrity of the central nervous system. It has been reported that the apoE genetic polymorphism is associated with several components of childhood and adolescent temperament. To study the effect of the presence of the apoE epsilon4 allele on adult personality factors, tridimensional personality questionnaire (TPQ) scores were compared for epsilon4 and non-epsilon4 carriers in a sample population consisting of 135 young females. No significant differences were demonstrated comparing the scores for the two groups. Our findings suggest that the investigated apoE polymorphism does not play a major role in personality trait factors, as assessed by TPQ.